Apple punished users for switching to Android

The fruity cargo cult Apple is being sued for punishing its iPhone users for switching to Android.
The suit was filed by a former iPhone customer, Adrienne Moore. who alleges she changed to a non-Apple device and stopped getting text messages from Apple

Apple clock details leaked

The much hyped vapourware the iWatch has been leaked to a loud sounding yawn from the rest of the world.
Design details of the Apple iWatch have been revealed by an analyst, Brian Blair of Rosenblatt Securities, who claims to have got the information from within Apple's supply chain.
If the leak is true, then Apple really is out of ideas and it explains

Google Glass is ancient technology

While the US press goes on about how clever Google is for inventing its Glass project it appears to be forgetting that the British came up with the idea more than a decade ago but could not be bothered with it.
Vaccum cleaner maker Dyson,

Apple installs Bing

It looks like the long running feud between Apple and Microsoft is over as both sides have a common enemy in Google.
Apple has announced that it is getting rid of Google's search engine from its shiny rounded rectangular toys in favour of Microsoft's Bing.
Bing will find its way into OS X 10.10, the new desktop operating system from Apple.
Other signs have followed that Microsoft

Microsoft leans on US government over NSA

A year after Snowden, Microsoft has unleashed its nastiest lobbying hounds into Washington to demand reform. According to PC World, Vole is demanding that government search warrants should end at the country's borders. Redmond is getting a canning overseas because

Chrome moves to 64 bit beta

Google has released a beta version of a 64-bit version of Chrome which looks stable enough to give its 32 bit version a good kicking. Early users say that it is faster, stable and has better security capabilities than the current 32 bit version of Chrome. The beta version of the 64-bit

Google shows off new Tegra based tablet

Google's Advanced Technology and Projects group has released details of a new Protect Tango tablet based around an Nvidia Tegra K1.
The seven inch tablet comes with 4GB of RAM, 128GB of storage and WiFi, Bluetooth, and 4G LTE.
The Tegra K1 was announced at CES and

Chrome is now the world's most popular browser

Search engine Google's Chrome browser has officially overtaken Microsoft's Internet Explorer as the most popular web browser in the US. According to Adobe Digital Index Chrome has 31.8 percent of the combined desktop and mobile internet market which means Google's freeware is

Apple investigated in EU tax probe

The European Commission has announced that it will launch a formal investigation on into Apple somewhat dodgy tax scheme.
The news follows a statement from the EU's competition authority last year that it was looking into corporate tax arrangements in several member states and

Apple will help people find their cars

Presstitutes working for the Tame Apple Press are getting all excited about a feature which will help the absent minded remember where they left their car.
The news has been around since September, but like many things Applish, like the iWatch, nothing really happened. Despite its software compontant it was not mentioned during WWDC

Facebook allows users to skip targeted adverts

Social notworking site, Facebook, will allow users who are annoyed by the targeted ads that pop up in their News Feed to opt out of them.
Facebook collects all kinds of information on its users and uses that information to serve up targeted ads and this worries people who find it a bit creepy to have a social network tracking

Chinese reveal Microsoft's control of Android

Microsoft has had a secret list of patents which amounts to a hold that Vole has over the Android operating system.
We say secret, but it appears that a Chinese government action has forced Vole to make the list public for the first time.
According to Ars Technica, Microsoft has revealed a few of those patents since as it has unleashed litigation against Android device makers. But for the most part, they've remained secret.
Now a list of hundreds of patents that Microsoft believes entitle it to royalties over

Google And Apple Fight For Your Heart As Healthcare Defines The Latest Smartphone War

Just as Apple declared war on Google at the recent WWDC with aggressive moves into the mobile search space, Google are ready to strike back with ‘Google Fit’. First reported by Forbes’ Parmy Olsen, the cloud-based heath aggregator

Define Luminosity

The brightness of a color based on a scale from black to white on your monitor.

Loopback Address

The address of the local computer used for routing outgoing packets back to the source computer. This address is used primarily for testing.

Logon Script Path

A sequence of directory names that specifies the location of the logon script. When a user logs on, the authenticating computer locates the specified logon script (if one has been assigned to that user account) by following that computer's local logon script path (usually systemroot\System32\Repl\Import\Scripts).

Logical Drive

A volume that you create within an extended partition on a basic master boot record (MBR) disk. Logical drives are similar to primary partitions, except that you are limited to four primary partitions per disk, whereas you can create an unlimited number of logical drives per disk. A logical drive can be formatted and assigned a drive letter.

Local Computer

The computer that you are currently logged on to as a user. More generally, a local computer is a computer that you can access directly without using a communications line or a communications device, such as a network adapter or a modem.

Local Area Network (LAN)

A communications network connecting a group of computers, printers, and other devices located within a relatively limited area (for example, a building). A LAN allows any connected device to interact with any other on the network.

What is LCD? Define LCD, Liquid Crystal Display (LCD)

A type of display used in digital watches and many portable computers. LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.

Link Control Protocol (LCP)

A PPP control protocol that negotiates link and PPP parameters to dynamically configure the data-link layer of a PPP connection.

Line Printer Remote (LPR)

A connectivity utility that runs on client systems and is used to print files to a computer running an LPD server.

Line Printer Daemon (LPD)

A service on the print server that receives documents (print jobs) from Line Printer Remote (LPR) utilities running on client systems.

Lightweight Directory Access Protocol (LDAP)

The primary access protocol for Active Directory. Lightweight Directory Access Protocol (LDAP) version 3 is defined by a set of Proposed Standard documents in Internet Engineering Task Force (IETF) RFC 2251.

LDAP Data Interchange Format (LDIF)

Files that contain LDAP instructions that manipulate directory information. Before the LDAP commands in an LDIF file are carried out, they can be read or modified, providing an opportunity for fine-tuning.

Define Latency, What is Latency?

In Active Directory replication, the delay between the time an update is applied to a given replica and the time it is applied to some other replica. Latency is sometimes referred to as propagation delay.

LAN emulation server (LES)

The central control point for an emulated local area network (ELAN). Enables LAN emulation clients to join the ELAN and resolves LAN addresses to ATM addresses.

LAN emulation configuration server

The service that assigns individual local area network emulation (LANE) clients to particular emulated local area networks (ELANs) by directing them to the LAN emulation server (LES).

LAN emulation client (LEC)

The client on an ELAN that performs data forwarding, address resolution, and other control functions. The LEC resides on end stations in an ELAN.

LAN emulation (LANE)

A set of protocols that allow existing Ethernet and Token Ring LAN services to overlie an ATM network. LANE allows connectivity among LAN- and ATM-attached stations.

What is label?

Each part of a full DNS domain name that represents a node in the domain namespace tree. Domain names are made up of a sequence of labels, such as the three labels (example, microsoft, and com) that make up the DNS domain name example.microsoft.com. Each label used in a DNS name must be 63 bytes or less in character length.

L2TP (Layer 2 Tunneling Protocol)

An industry-standard Internet tunneling protocol. Unlike Point-to-Point Tunneling Protocol (PPTP), L2TP does not require IP connectivity between the client workstation and the server. L2TP requires only that the tunnel medium provide packet-oriented point-to-point connectivity. The protocol can be used over media such as ATM, Frame Relay, and X.25. L2TP provides the same functionality as PPTP. Based on Layer 2 Forwarding (L2F) and PPTP specifications, L2TP allows clients to set up tunnels across intervening networks.

Key Distribution Center (KDC)

A network service that supplies session tickets and temporary session keys used in the Kerberos V5 authentication protocol. In Windows 2000 and Windows XP, the KDC runs as a privileged process on all domain controllers.

Define Key?

In Registry Editor, a folder that appears in the left pane of the Registry Editor window. A key can contain subkeys and value entries. For example, Environment is a key of HKEY_CURRENT_USER.
In IP security (IPSec), a value used in combination with an algorithm to encrypt or decrypt data. Key settings for IP security are configurable to provide greater security.

What is Kernel?

The core of layered architecture that manages the most basic operations of the operating system and the computer's processor. The kernel schedules different blocks of executing code, called threads, for the processor to keep it as busy as possible and coordinates multiple processors to optimize performance. The kernel also synchronizes activities among Executive-level subcomponents, such as I/O Manager and Process Manager, and handles hardware exceptions and other hardware-dependent functions. The kernel works closely with the hardware abstraction layer.

ISDN (Integrated Services Digital Network)

A high-speed digital telephone service that can dramatically increase the speed at which you connect to the Internet or to your corporate LAN (local area network). ISDN can operate at 128 kilobytes per second (Kbps), which is five or more times faster than many analog modems.

ISA expansion slot

A connection socket for a peripheral designed to the Industry Standard Architecture (ISA) on a computer motherboard.

IPX/SPX

Transport protocols used in Novell NetWare networks, which together correspond to the combination of TCP and IP in the TCP/IP protocol suite. Windows implements IPX through NWLink.

IP Address resource

A 32-bit number in dotted decimal format that represents an Internet Protocol (IP) address and is supported as a cluster resource by a Resource DLL provided with Windows.

IP address

A 32-bit address used to identify a node on an IP internetwork. Each node on the IP internetwork must be assigned a unique IP address, which is made up of the network ID, plus a unique host ID. This address is typically represented with the decimal value of each octet separated by a period (for example, 192.168.7.27). In this version of Windows, you can configure the IP address statically or dynamically through DHCP

intersite messaging service (ISM)

A service that supports transports for asynchronous, site-to-site messaging. Each transport serves two major roles: send/receive and topology queries (such as, what are the various sites connected by this transport, and at what cost?). The intersite messaging services shipped in Windows are RPC and SMTP (mail).

Interrupt Request (IRQ) lines

Hardware lines over which devices can send signals to get the attention of the processor when the device is ready to accept or send information. Each device must have a unique IRQ line.

Internet service provider (ISP)

A company that provides individuals or companies access to the Internet and the World Wide Web. An ISP provides a telephone number, a user name, a password, and other connection information so users can connect their computers to the ISP's computers. An ISP typically charges a monthly or hourly connection fee.

Internet Protocol security (IPSec)

A set of industry-standard, cryptography-based protection services and protocols. IPSec protects all protocols in the TCP/IP protocol suite and Internet communications using L2TP.

Internet Protocol (IP)

A routable protocol in the TCP/IP protocol suite that is responsible for IP addressing, routing, and the fragmentation and reassembly of IP packets.

Internet Information Services (IIS)

Software services that support Web site creation, configuration, and management, along with other Internet functions. Internet Information Services include Network News Transfer Protocol (NNTP), File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP).

Internet Engineering Task Force (IETF)

An open community of network designers, operators, vendors, and researchers concerned with the evolution of Internet architecture and the smooth operation of the Internet. Technical work is performed by working groups organized by topic areas (such as routing, transport, and security) and through mailing lists. Internet standards are developed in IETF Requests for Comments (RFCs), which are a series of notes that discuss many aspects of computing and computer communication, focusing on networking protocols, programs, and concepts.

Internet Control Message Protocol (ICMP)

A required maintenance protocol in the TCP/IP suite that reports errors and allows simple connectivity. ICMP is used by the Ping tool to perform TCP/IP troubleshooting.

International Telecommunication Union - Telecommunication [Standardization Sector] (ITU-T)

The sector of the International Telecommunication Union (ITU) responsible for telecommunication standards.
ITU-T replaces the Comite Consultatif International Telegraphique et Telephonique (CCITT). Its responsibilities include standardizing modem design and operations, and standardizing protocols for networks and facsimile transmission. ITU is an international organization within which governments and the private sector coordinate global telecom networks and services.

Integrated Services Digital Network (ISDN)

A digital phone line used to provide higher bandwidth. ISDN in North America is typically available in two forms: Basic Rate Interface (BRI) consists of 2 B-channels at 64 kilobits per second (Kbps) and a D-channel at 16 Kbps; Primary Rate Interface (PRI) consists of 23 B-channels at 64 Kbps and a D-channel at 64 Kbps. An ISDN line must be installed by the phone company at both the calling site and the called site.

Integrated Device Electronics (IDE)

A type of disk-drive interface in which the controller electronics reside on the drive itself, eliminating the need for a separate adapter card. IDE offers advantages such as look-ahead caching to increase overall performance.

Input/Output (I/O) Port

A channel through which data is transferred between a device and the microprocessor. The port appears to the microprocessor as one or more memory addresses that it can use to send or receive data.

Input Method Editor (IME)

Programs used to enter the thousands of different characters in written Asian languages with a standard 101-key keyboard. An IME consists of both an engine that converts keystrokes into phonetic and ideographic characters and a dictionary of commonly used ideographic words. As the user enters keystrokes, the IME engine attempts to identify which character or characters the keystrokes should be converted into.

Infrared Port

An optical port on a computer that enables communication with other computers or devices by using infrared light, without cables. Infrared ports can be found on some portable computers, printers, and cameras.

Infrared Network Connection

A direct or incoming network connection to a remote access server using an infrared port.

Infrared File Transfer

Wireless file transfer between a computer and another computer or device using infrared light.

Infrared Device

A computer, or a computer peripheral such as a printer, that can communicate using infrared light.

Infrared Data Association (IrDA)

The industry organization of computer, component, and telecommunications vendors who establish the standards for infrared communication between computers and peripheral devices, such as printers.

Infrared (IR)

Light that is beyond red in the color spectrum. While the light is not visible to the human eye, infrared transmitters and receivers can send and receive infrared signals.

Incremental Zone Transfer (IXFR)

An alternate query type that can be used by some DNS servers to update and synchronize zone data when a zone is changed. When incremental zone transfer is supported between DNS servers, servers can keep track of and transfer only those incremental resource record changes between each version of the zone.

In-addr.arpa domain

A special top-level DNS domain reserved for reverse mapping of IP addresses to DNS host names.

IIS Server Instance resource

A server-instance designation used with Internet Information Services (IIS) that supports the WWW and FTP services. IIS server instances are supported as cluster resources by a Resource DLL. IIS Server Instance resources may have dependencies on IP Address resources, Network Name resources, and Physical Disk resources. Access information for server instances does not fail over.

IEEE 1394 connector

A type of connector that enables you to connect and disconnect high-speed serial devices. An IEEE 1394 connector is usually on the back of your computer near the serial port or the parallel port.

If a device is IEEE 1394 compatible, you can connect the device to the IEEE 1394 connector while the computer is running and Windows will detect the device and inform you when it is ready for use. Similarly, you can unplug the device while the computer is running, but you should use the Add Hardware Wizard to inform Windows that you are unplugging the device. Windows will then inform you when the device can be unplugged from the computer.

The IEEE 1394 bus is used primarily to connect high-end digital video and digital audio devices to your computer; however, some hard disks, printers, scanners, and DVD drives can also be connected to your computer using the IEEE 1394 connector.

IEEE 1394

A standard for high-speed serial devices such as digital video and digital audio editing equipment.

What is Icon?

A small image displayed on the screen to represent an object that can be manipulated by the user. Icons serve as visual mnemonics and allow the user to control certain computer actions without having to remember commands or type them at the keyboard.

Hypertext Transfer Protocol (HTTP)

The protocol used to transfer information on the World Wide Web. An HTTP address (one kind of Uniform Resource Locator [URL]) takes the form: http://www.microsoft.com.

Hypertext Markup Language (HTML)

A simple markup language used to create hypertext documents that are portable from one platform to another. HTML files are simple ASCII text files with codes embedded (indicated by markup tags) to denote formatting and hypertext links.

Define Hyperlink?

Colored and underlined text or a graphic that you click to go to a file, a location in a file, an HTML page on the World Wide Web, or an HTML page on an intranet. Hyperlinks can also go to newsgroups and to Gopher, Telnet, and FTP sites.

In Windows folders, hyperlinks are text links that appear in the folder's left pane. You can click these links to perform tasks, such as moving or copying a file, or to go to other places on your computer, such as the My Documents folder or Control Panel.

What is Hub?

The position of a color along the color spectrum. For example, green is between yellow and blue. This attribute can be set using Display in Control Panel.

DVD

DVD (sometimes explained as "digital video disc" or "digital versatile disc"[5][6]) is a digital optical disc storage format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs can be played in many types of players, including DVD players. DVDs offer higher storage capacity than compact discs while having the same dimensions.

Pre-recorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are known as DVD-ROM, because data can only be read and not written or erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased multiple times.

DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoring DVD discs written in a special AVCHD format to hold high definition material (often in conjunction with AVCHD format camcorders). DVDs containing other types of information may be referred to as DVD data discs.

DVD Specifications

The DVD specifications created and updated by the DVD Forum are published as so-called DVD Books (e.g. DVD-ROM Book, DVD-Audio Book, DVD-Video Book, DVD-R Book, DVD-RW Book, DVD-RAM Book, DVD-AR Book, DVD-VR Book, etc.).[1][2][3]

Some specifications for mechanical, physical and optical characteristics of DVD optical discs can be downloaded as freely available standards from the ISO website.[12] There are also equivalent European Computer Manufacturers Association (ECMA) standards for some of these specifications, such as Ecma-267 for DVD-ROMs.[13] Also, the DVD+RW Alliance publishes competing recordable DVD specifications such as DVD+R, DVD+R DL, DVD+RW or DVD+RW DL. These DVD formats are also ISO standards.[14][15][16][17]

Some of DVD specifications (e.g. for DVD-Video) are not publicly available and can be obtained only from the DVD Format/Logo Licensing Corporation for a fee of US $5000.[18][19] Every subscriber must sign a non-disclosure agreement as certain information in the DVD Book is proprietary and confidential.[18]

DVD recordable and rewritable

HP initially developed recordable DVD media from the need to store data for backup and transport.[20] DVD recordables are now also used for consumer audio and video recording. Three formats were developed: DVD-R/RW, DVD+R/RW (plus), and DVD-RAM. DVD-R is available in two formats, General (650 nm) and Authoring (635 nm), where Authoring discs may be recorded with CSS encrypted video content but General discs may not.[21]

Although most DVD writers can nowadays write the DVD+R/RW and DVD-R/RW formats (usually denoted by "DVD±RW" and/or the existence of both the DVD Forum logo and the DVD+RW Alliance logo), the "plus" and the "dash" formats use different writing specifications. Most DVD readers and players play both kinds of discs, though older models can have trouble with the "plus" variants.

Some first generation DVD players would cause damage to DVD±R/RW/DL when attempting to read them.[citation needed]

The form of the spiral groove that makes up the structure of a recordable DVD encodes unalterable identification data known as Media Identification Code (MID). The MID contains data such as the manufacturer and model, byte capacity, allowed data rates (also known as speed), etc

DVD Dual-layer recording

Dual-layer recording (sometimes also known as double-layer recording) allows DVD-R and DVD+R discs to store significantly more data—up to 8.5 gigabytes per disc, compared with 4.7 gigabytes for single-layer discs.[22] Along with this, DVD-DLs have slower write speeds as compared to ordinary DVDs. When played, a slight transition can sometimes be seen in the playback when the player changes layers. DVD-R DL was developed for the DVD Forum by Pioneer Corporation; DVD+R DL was developed for the DVD+RW Alliance by Philips and Mitsubishi Kagaku Media (MKM).[23]

A dual-layer disc differs from its usual DVD counterpart by employing a second physical layer within the disc itself. The drive with dual-layer capability accesses the second layer by shining the laser through the first semitransparent layer. In some DVD players, the layer change can exhibit a noticeable pause, up to several seconds.[24] This caused some viewers to worry that their dual-layer discs were damaged or defective, with the end result that studios began listing a standard message explaining the dual-layer pausing effect on all dual-layer disc packaging.

DVD recordable discs supporting this technology are backward-compatible with some existing DVD players and DVD-ROM drives.[23] Many current DVD recorders support dual-layer technology, and the price is now comparable to that of single-layer drives, although the blank media remain more expensive. The recording speeds reached by dual-layer media are still well below those of single-layer media.

Dual layer DVDs are recorded using Opposite Track Path (OTP).[25] DVD-ROM discs mastered for computer use are produced with track 0 starting at the inside diameter (as is the case with a single layer). Track 1 then starts at the outside diameter. DVD video discs are mastered slightly differently. The video is divided between the layers such that layer 1 can be made to start at the same diameter that layer 0 finishes. This speeds up the transition as the layer changes because although the laser does have to refocus on layer 1, it does not have to skip across the disc to find it.

DVD Capacity

The basic types of DVD (12 cm diameter, single-sided or homogeneous double-sided) are referred to by a rough approximation of their capacity in gigabytes. In draft versions of the specification, DVD-5 indeed held five gigabytes, but some parameters were changed later on as explained above, so the capacity decreased. Other formats, those with 8 cm diameter and hybrid variants, acquired similar numeric names with even larger deviation.
The 12 cm type is a standard DVD, and the 8 cm variety is known as a MiniDVD. These are the same sizes as a standard CD and a mini-CD, respectively. The capacity by surface (MiB/cm²) varies from 6.92 MiB/cm² in the DVD-1 to 18.0 MiB/cm² in the DVD-18.
As with hard disk drives, in the DVD realm, gigabyte and the symbol GB are usually used in the SI sense (i.e., 10⁹, or 1,000,000,000 bytes). For distinction, a gigabyte is normally used in the binary sense (i.e., 1024³ (2³⁰), or 1,073,741,824 bytes), which in SI nomenclature is called a gibibyte (GiB).
Each DVD sector contains 2,418 bytes of data, 2,048 bytes of which are user data. There is a small difference in storage space between + and - (hyphen) formats:

Scan of a DVD 4.5 capacity disc

Capacity and nomenclature
SS = single-sided, DS = double-sided, SL = single-layer, DL = dual-layer

Designation		Sides	Layers (total)	Diameter (cm)	Capacity
					(GiB)
DVD-1	SS SL	1	1	8	1.36
DVD-2	SS DL	1	2	8	2.47
DVD-3	DS SL	2	2	8	2.72
DVD-4	DS DL	2	4	8	4.95
DVD-5	SS SL	1	1	12	4.37
DVD-9	SS DL	1	2	12	7.95
DVD-10	DS SL	2	2	12	8.75
DVD-14	DS SL+DL	2	3	12	12.33
DVD-18	DS DL	2	4	12	15.90

DVD Laser and optics

DVD uses 650 nm wavelength laser diode light, as opposed to 780 nm for CD. This shorter wavelength etches a smaller pit on the media surface compared to CDs (0.74 µm for DVD versus 1.6 µm for CD), allowing in part for DVD's increased storage capacity.

In comparison, Blu-ray Disc, the successor to the DVD format, uses a wavelength of 405 nm, and one dual-layer disc has a 50 GB storage capacity.

DVD Transfer rates

Read and write speeds for the first DVD drives and players were of 1,385 kB/s (1,353 KiB/s); this speed is usually called "1×". More recent models, at 18× or 20×, have 18 or 20 times that speed. Note that for CD drives, 1× means 153.6 kB/s (150 KiB/s), about one-ninth as swift.^[28][30]

DVD drive speeds

Drive speed	Data rate		~Write time (minutes)[31]
	Mbit/s	MB/s	Single-Layer	Dual-Layer
1×	11.08	1.39	57	103
2×	22.16	2.77	28	51
2.4×	26.59	3.32	24	43
2.6×	28.81	3.60	22	40
4×	44.32	5.54	14	26
6×	66.48	8.31	9	17
8×	88.64	11.08	7	13
10×	110.80	13.85	6	10
12×	132.96	16.62	5	9
16×	177.28	22.16	4	6
18×	199.44	24.93	3	6
20×	221.60	27.70	3	5
22×	243.76	30.47	3	5
24×	265.92	33.24	2	4

Digital Video Disk (DVD) Longevity

DVD longevity is measured by how long the data remains readable from the disc, assuming compatible devices exist that can read it: that is, how long the disc can be stored until data is lost. Numerous factors affect longevity: composition and quality of the media (recording and substrate layers), humidity and light storage conditions, the quality of the initial recording (which is sometimes a matter of mutual compatibility of media and recorder), etc.[42] According to NIST, "[a] temperature of 18°C and 40% RH [Relative Humidity] would be considered suitable for long-term storage. A lower temperature and RH is recommended for extended-term storage."[43]

According to the Optical Storage Technology Association (OSTA), "Manufacturers claim lifespans ranging from 30 to 100 years for DVD, DVD-R and DVD+R discs and up to 30 years for DVD-RW, DVD+RW and DVD-RAM." [44]

According to a NIST/LoC research project conducted in 2005-2007 using accelerated life testing, "There were fifteen DVD products tested, including five DVD-R, five DVD+R, two DVD-RW and three DVD+RW types. There were ninety samples tested for each product. [...] Overall, seven of the products tested had estimated life expectancies in ambient conditions of more than 45 years. Four products had estimated life expectancies of 30-45 years in ambient storage conditions. Two products had a estimated life expectancy of 15-30 years and two products had estimated life expectancies of less than 15 years when stored in ambient conditions." The life expectancies for 95% survival estimated in this project by type of product are tabulated below:[42]
Disc type        0-15 years 15-30 years   30-45 years           over 45 years
DVD-R             20%        20%               0%                               60%
DVD+R            20%        0%               40%                               40%
DVD-RW           0%        0%               50%                               50%
DVD+RW          0%        33.3%          33.3%                            33.3%

Digital Video Disk (DVD) Definition

DVD (sometimes explained as "digital video disc" or "digital versatile disc"[5][6]) is a digital optical disc storage format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs can be played in many types of players, including DVD players. DVDs offer higher storage capacity than compact discs while having the same dimensions.

Pre-recorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are known as DVD-ROM, because data can only be read and not written or erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased multiple times.

DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoring DVD discs written in a special AVCHD format to hold high definition material (often in conjunction with AVCHD format camcorders). DVDs containing other types of information may be referred to as DVD data discs.

Host Name

The DNS name of a device on a network. These names are used to locate computers on the network. To find another computer, its host name must either appear in the Hosts file or be known by a DNS server. For most Windows computers, the host name and the computer name are the same.

Host Definition

A Windows computer that runs a server program or service used by network or remote clients. For Network Load Balancing, a cluster consists of multiple hosts connected over a local area network (LAN).

Define Hive

A section of the registry that appears as a file on your hard disk. The registry subtree is divided into hives (named for their resemblance to the cellular structure of a beehive). A hive is a discrete body of keys, subkeys, and values that is rooted at the top of the registry hierarchy. A hive is backed by a single file and a .log file, which are in the systemroot\System32\Config or the systemroot\Profiles\username folders.
By default, most hive files (Default, SAM, Security, and System) are stored in the systemroot\System32\Config folder. The systemroot\Profiles folder contains the user profile for each user of the computer. Because a hive is a file, it can be moved from one system to another. However, you must use the Registry Editor to edit the file.

A chart consisting of horizontal or vertical bars, the widths or heights of which represent the values of certain data.

High Contrast

A display feature that instructs programs to change the color scheme to a high-contrast scheme and to increase legibility whenever possible.

Hibernation

A state in which your computer shuts down after saving everything in memory on your hard disk. When you bring your computer out of hibernation, all programs and documents that were open are restored to your desktop.

Hexadecimal

A base-16 number system represented by the digits 0 through 9 and the uppercase or lowercase letters A (equivalent to decimal 10) through F (equivalent to decimal 15).

Hash-based Message Authentication Mode (HMAC)

A mechanism for message authentication using cryptographic hash functions. HMAC can be used with any iterative cryptographic hash function (for example, MD5 and SHA-1) in combination with a secret shared key. The cryptographic strength of HMAC depends on the properties of the underlying hash function.

Hardware Type

A classification for similar devices. For example, Imaging Device is a hardware type for digital cameras and scanners.

Hardware Profile

Data that describes the configuration and characteristics of specific computer equipment. This information can be used to configure computers for using peripheral devices.

Hardware Configuration

Resource settings that have been allocated for a specific device. Each device on your computer has a hardware configuration, which may consist of IRQ lines, DMA, an I/O port, or memory address settings.

Hardware Compression

A feature available on some tape devices that automatically compresses the data that is being stored on the device. This is usually an option that is turned on or off in a backup program.

Define Hardware, What is Hardware?

The physical components of a computer system, including any peripheral equipment such as printers, modems, and mouse devices.

Define Hard Disk, What is Hard Disk?

A device, also called hard disk drive, that contains one or more inflexible platters coated with material in which data can be recorded magnetically with read/write heads. The hard disk exists in a sealed case that protects it and allows the head to fly 10 millionths to 25 millionths of an inch above the surface of a platter. Data can both be stored and accessed much more quickly than on a floppy disk.

Handwriting Recognition

The ability to interpret handwritten text and convert it into computer-readable text. Handwriting recognition programs allow you to enter text using a pen stylus or other handwriting input device, rather than a keyboard.

Handwriting Input Device

A tool, such as a digital pen and tablet, used to enter text by writing instead of typing. Along with writing tablets, you can use
3-D drawing or Computer Aided Drafting (CAD) tablets, or a tablet-PC. You can also write by moving your mouse on the mouse pad.

Handshaking

A series of signals acknowledging that communication can take place between computers or other devices. A hardware handshake is an exchange of signals over specific wires (other than the data wires), in which each device indicates its readiness to send or receive data. A software handshake consists of signals transmitted over the same wires used to transfer data, as in modem-to-modem communications over telephone lines.

Half-Duplex

A system capable of transmitting information in only one direction at a time over a communications channel.

GUID partition table (GPT)

A disk-partitioning scheme that is used by the Extensible Firmware Interface (EFI) in Itanium-based computers. GPT offers more advantages than master boot record (MBR) partitioning because it allows up to 128 partitions per disk, provides support for volumes up to 18 exabytes in size, allows primary and backup partition tables for redundancy, and supports unique disk and partition IDs (GUIDs).

Guest Account

A built-in account used to log on to a computer running Windows when a user does not have an account on the computer or domain, or in any of the domains trusted by the computer's domain.

Group Policy object

A collection of Group Policy settings. Group Policy objects are essentially the documents created by the Group Policy snap-in, a Windows utility. Group Policy objects are stored at the domain level, and they affect users and computers contained in sites, domains, and organizational units. In addition, each Windows computer has exactly one group of settings stored locally, called the local Group Policy object.

Group Policy

The Microsoft Management Console (MMC) snap-in that is used to edit Group Policy objects.

Group Name

A unique name identifying a local group or a global group to Windows. A group's name cannot be identical to any other group name or user name in its own domain or computer.

Group Memberships

The groups to which a user account belongs. Permissions and rights granted to a group are also provided to its members. In most cases, the actions a user can perform in Windows are determined by the group memberships of the user account to which the user is logged on.

Group Account

A collection of user accounts. By making a user account a member of a group, you give the related user all the rights and permissions granted to the group.

Graphics Mode

A display mode in which lines and characters on the screen are drawn pixel by pixel. Graphics mode displays images by grouping individual dots into shapes, such as the arrowhead of a mouse pointer. It can also preview character formatting, such as boldface and italics, as it will appear in print.

Glue Record

A resource record for out-of-zone information used to provide helpful pointer information for locating DNS servers that have been delegated authority for specific subdomains derived from a zone's domain of origin. These records are used to glue zones together and provide an effective delegation and referral path for other DNS servers to follow when performing a recursive lookup to fully resolve a name.

Glue Chasing

The follow-up queries or successive lookups that are made to resolve glue records in a zone to other remote DNS servers that are authoritative for a derivative zone. When glue chasing is performed, name server (NS) resource records for delegated DNS servers are chased, or followed, by using successive queries to resolve the servers named in NS records to their host address (A) resource records and to obtain server IP addresses.

Global Group

A security or distribution group that can have users, groups, and computers from its own domain as members. Global security groups can be granted rights and permissions on resources in any domain in the forest. Global groups cannot be created or maintained on computers running Windows XP Professional. However, for Windows XP Professional computers that participate in a domain, domain global groups can be granted rights and permissions at those workstations and can become members of local groups at those workstations.

Global Catalog

A domain controller that contains a partial replica of every domain in Active Directory. In other words, a global catalog holds a replica of every object in Active Directory, but with a limited number of each object's attributes. The global catalog stores those attributes most frequently used in search operations (such as a user's first and last names) and those attributes required to locate a full replica of the object.
The Active Directory replication system builds the global catalog automatically. The attributes replicated into the global catalog include a base set defined by Microsoft. Administrators can specify additional properties to meet the needs of their installation.

Global Account

In an Active Directory network, a normal user account in a user's domain. Most user accounts are global accounts. If there are multiple domains in the network, it is best if each user in the network has only one user account in only one domain, and each user's access to other domains is accomplished through the establishment of domain trust relationships.

Game Port

An input/output connector to which you attach a joy stick or other game device to your computer. It is typically a 15-pin socket on the back of a PC.

Define Gigabyte (GB)

1,024 megabytes, though often interpreted as approximately one billion bytes.

GDI objects

Objects from the Graphics Device Interface (GDI) library of application programming interfaces (APIs) for graphics output devices. In Task Manager, the number of GDI objects currently used by a process.

Fully Qualified Domain Name (FQDN)

A DNS domain name that has been stated unambiguously so as to indicate with absolute certainty its location in the domain namespace tree. Fully qualified domain names differ from relative names in that they are typically stated with a trailing period (.) - for example, host.example.microsoft.com. - to qualify their position to the root of the namespace.

Full Zone Transfer (AXFR)

The standard query type supported by all DNS servers to update and synchronize zone data when the zone has been changed. When a DNS query is made using AXFR as the specified query type, the entire zone is transferred as the response.

Front-End Processor (FEP)

In communications, a computer that is located between communications lines and a main (host) computer and used to relieve the host of tasks related to communications; sometimes considered synonymous with communications controller. A front-end processor is dedicated entirely to handling transmitted information, including error detection and control; receipt, transmission, and possibly encoding of messages; and management of the lines running to and from other devices.

What is FORTEZZA?

A family of security products, including PCMCIA-based cards, compatible serial port devices, combination cards (such as FORTEZZA/Modem and FORTEZZA/Ethernet), server boards, and others. FORTEZZA is a registered trademark held by the National Security Agency.

What is Foreign Computer?

A computer that uses another message queuing system but, through a connector application, can exchange messages with computers that run Message Queuing.

Foreground Program

The program that runs in the active window (the uppermost window with the highlighted title bar). The foreground program responds to commands issued by the user.

Font Cartridge

A plug-in unit available for some printers that contains fonts in several styles and sizes. As with downloadable fonts, printers using font cartridges can produce characters in sizes and styles other than those created by the fonts built into it.

Define Firewall, What is Firewall?

A combination of hardware and software that provides a security system, usually to prevent unauthorized access from outside to an internal network or intranet. A firewall prevents direct communication between network and external computers by routing communication through a proxy server outside of the network. The proxy server determines whether it is safe to let a file pass through to the network. A firewall is also called a security-edge gateway.

FilterKeys

A keyboard feature that instructs your keyboard to ignore brief or repeated keystrokes. You can also adjust the keyboard repeat rate, which is the rate at which a key repeats when you hold it down.

Filtering Mode

For Network Load Balancing, the method by which network traffic inbound to a cluster is handled by the hosts within the cluster. Traffic can either be handled by a single server, load balanced among the hosts within the cluster, or disabled completely.

Define Filter, What is filter?

For Indexing Service, software that extracts content and property values from a document in order to index them.
For IPSec, a specification of IP traffic that provides the ability to trigger security negotiations for a communication based on the source, destination, and type of IP traffic.

File Transfer Protocol (FTP)

A member of the TCP/IP suite of protocols, used to copy files between two computers on the Internet. Both computers must support their respective FTP roles: one must be an FTP client and the other an FTP server.

Explicit Permissions

Permissions on an object that are automatically assigned when the object is created, or specifically assigned or changed by the owner of the object.

Cross-reference object

Objects in which Active Directory stores information about directory partitions and external directory services. An example of an external directory service is another LDAP-compliant directory.

Expire Interval

For DNS, the number of seconds that DNS servers operating as secondary masters for a zone will use to determine if zone data should be expired when the zone is not refreshed and renewed.

Extended Characters

Any of the 128 additional characters in the extended ASCII (8-bit) character set. These characters include those in several non-English languages, such as accent marks, and special symbols used for creating pictures.

File and Print Servers for Macintosh

A software component that allows Macintosh users access to a computer running any version of the Windows Server family. The services provided with this component allow personal computer and Macintosh users to share files and resources, such as printers on the AppleTalk network or printers attached to the Windows server.

File Allocation Table (FAT)

A file system used by MS-DOS and other Windows-based operating systems to organize and manage files. The file allocation table (FAT) is a data structure that Windows creates when you format a volume by using the FAT or FAT32 file systems. Windows stores information about each file in the FAT so that it can retrieve the file later.

Federal Information Processing Standard 140-1 (FIPS 140-1)

A standard entitled Security Requirements for Cryptographic Modules. FIPS 140-1 describes government requirements that hardware and software cryptomodules should meet for Sensitive but Unclassified (SBU) use.

Fax Service, Define Fax

A system service that provides fax services to local and remote network clients. Fax services include receiving faxes and faxing documents, fax wizard messages, and e-mail messages.

Fault Tolerance

The ability of computer hardware or software to ensure data integrity when hardware failures occur. Fault tolerant features appear in many server operating systems and include mirrored volumes, RAID-5 volumes, and server clusters.

What is FAT32? Define FAT32

A derivative of the file allocation table (FAT) file system. FAT32 supports smaller cluster sizes and larger volumes than FAT, which results in more efficient space allocation on FAT32 volumes.

Failover

The process of taking resource groups offline on one node and bringing them back online on another node. When a resource group goes offline, all resources belonging to that group go offline. The offline and online transitions occur in a predefined order, with resources that are dependent on other resources taken offline before and brought online after the resources upon which they depend.

Failback Policy

Parameters that an administrator can set using Cluster Administrator that affect failback operations.

Define Failback

The process of moving resources, either individually or in a group, back to their preferred node after the node has failed and come back online.

External Network Number

A 4-byte hexadecimal number used for addressing and routing purposes. The external network number is associated with physical network adapters and networks. To communicate with each other, all computers on the same network that use a specific frame type must have the same external network number. All external network numbers must be unique to the IPX internetwork.

Extensible Markup Language (XML)

A meta-markup language that provides a format for describing structured data. This facilitates more precise declarations of content and more meaningful search results across multiple platforms. In addition, XML will enable a new generation of Web-based data viewing and manipulation applications.

Extensible Firmware Interface (EFI)

In computers with the Intel Itanium processor, the interface between a computer's firmware, hardware, and the operating system. The Extensible Firmware Interface (EFI) defines a new partition style called GUID partition table (GPT). EFI serves the same purpose for Itanium-based computers as the BIOS found in x86-based computers. However, it has expanded capabilities that provide a consistent way to start any compatible operating system and an easy way to add EFI drivers for new bootable devices without the need to update the computer's firmware.

Extensible Authentication Protocol (EAP)

An extension to the Point-to-Point Protocol (PPP) that allows for arbitrary authentication mechanisms to be employed for the validation of a PPP connection.

Extended Partition

A type of partition that you can create only on basic master boot record (MBR) disks. Extended partitions are useful if you want to create more than four volumes on a basic MBR disk. Unlike primary partitions, you do not format an extended partition with a file system and then assign a drive letter to it. Instead, you create one or more logical drives within the extended partition. After you create a logical drive, you format it and assign it a drive letter. An MBR disk can have up to four primary partitions, or three primary partitions, one extended partition, and multiple logical drives.

Extended Memory

Memory beyond one megabyte in 80286, 80386, 80486, and Pentium computers.

Express Message

For Message Queuing, a message that uses fewer resources and is faster than a recoverable message. However, because express messages are mapped to memory, they are lost if the computer storing them fails.

Explicit Permissions

Permissions on an object that are automatically assigned when the object is created, or specifically assigned or changed by the owner of the object.

Expire Interval

For DNS, the number of seconds that DNS servers operating as secondary masters for a zone will use to determine if zone data should be expired when the zone is not refreshed and renewed.

What is Expansion Slot?

A socket in a computer, designed to hold expansion boards and connect them to the system bus.

Expanded Memory

Type of memory that can be added to IBM personal computers. The use of expanded memory is defined by the Expanded Memory Specification (EMS), which supports memory boards containing RAM that can be enabled or disabled by software.

Everyone Category

In the Macintosh environment, one of the user categories to which you assign permissions for a folder. Permissions granted to everyone apply to all users who use the server, including guests.

Event Viewer

A component you can use to view and manage event logs, gather information about hardware and software problems, and monitor security events. Event Viewer maintains logs about program, security, and system events.

Event Logging

The process of recording an audit entry in the audit trail whenever certain events occur, such as services starting and stopping, or users logging on and off and accessing resources. You can use Event Viewer to review AppleTalk network integration events as well as Windows events.

Event Log Service

A service that records events in the system, security, and application logs. The Event Log service is located in Event Viewer.

Define Ethernet, What is Ethernet?

An IEEE 802.3 standard for contention networks. Ethernet uses a bus or star topology and relies on the form of access known as Carrier Sense Multiple Access with Collision Detection (CSMA/DC) to regulate communication line traffic. Network nodes are linked by coaxial cable, fiber-optic cable, or by twisted-pair wiring. Data is transmitted in variable-length frames containing delivery and control information and up to 1,500 bytes of data. The Ethernet standard provides for baseband transmission at 10 megabits (10 million bits) per second.

Error Detection

A technique for detecting when data is lost during transmission. This allows the software to recover lost data by notifying the transmitting computer that it needs to retransmit the data.

Environment Variable

A string consisting of environment information, such as a drive, path, or file name, associated with a symbolic name that can be used by Windows. You use System in Control Panel or the set command from the command prompt to define environment variables.

Enhanced Small Device Interface (ESDI)

A standard that can be used with high-capacity hard disks, floppy disk drives, and tape drives to allow these devices to communicate with a computer at high speeds.

Define Encryption

The process of disguising a message or data in such a way as to hide its substance.

Encrypting File System (EFS)

A feature in this version of Windows that enables users to encrypt files and folders on an NTFS volume disk to keep them safe from access by intruders.

Encrypted Password

A password that is scrambled. Encrypted passwords are more secure than plaintext passwords, which are susceptible to network sniffers.

Encapsulated PostScript (EPS) file

A file that prints at the highest possible resolution for your printer. An EPS file may print faster than other graphical representations. Some Windows-based and non-Windows-based graphical programs can import EPS files.

Emulated Local Area Network (ELAN)

A logical ATM network that emulates the services of an Ethernet or Token Ring LAN.

Embedded Object

Information created in another program that has been pasted inside your document. When information is embedded, you can edit the information in the new document using toolbars and menus from the original program.
To edit the embedded information, double-click it and the toolbars and menus from the program used to create the information appear. Embedded information is not linked to the original source. If you change information in one place, it is not updated in the other.

EFI system partition

On Itanium-based computers, a portion on a GUID partition table (GPT) disk that is formatted with the FAT file system and contains the files necessary to start the computer. Every Itanium-based computer must have at least one GPT disk with an EFI system partition. The EFI system partition serves the same purpose as the system volume found on x86-based computers.

Dynamic-Link Library (DLL)

An operating system feature that allows executable routines (generally serving a specific function or set of functions) to be stored separately as files with .dll extensions. These routines are loaded only when needed by the program that calls them.

Dynamic Volume

A volume that resides on a dynamic disk. Windows supports five types of dynamic volumes: simple, spanned, striped, mirrored, and RAID-5. A dynamic volume is formatted by using a file system, such as FAT or NTFS, and it has a drive letter assigned to it.

Dynamic Update

An updated specification to the Domain Name System (DNS) standard that permits hosts that store name information in DNS to dynamically register and update their records in zones maintained by DNS servers that can accept and process dynamic update messages.

Dynamic Storage

A storage method in Windows that allows disk and volume management without requiring operating system restart.

Dynamic Host Configuration Protocol (DHCP)

A TCP/IP service protocol that offers dynamic leased configuration of host IP addresses and distributes other configuration parameters to eligible network clients. DHCP provides safe, reliable, and simple TCP/IP network configuration, prevents address conflicts, and helps conserve the use of client IP addresses on the network.
DHCP uses a client/server model where the DHCP server maintains centralized management of IP addresses that are used on the network. DHCP-supporting clients can then request and obtain lease of an IP address from a DHCP server as part of their network boot process.

Dynamic Disk

A physical disk that can be accessed only by Windows 2000 and Windows XP. Dynamic disks provide features that basic disks do not, such as support for volumes that span multiple disks. Dynamic disks use a hidden database to track information about dynamic volumes on the disk and other dynamic disks in the computer. You convert basic disks to dynamic by using the Disk Management snap-in or the DiskPart command line utility. When you convert a basic disk to dynamic, all existing basic volumes become dynamic volumes.

dynamic data exchange (DDE)

A form of inter process communication (IPC) implemented in the Microsoft Windows family of operating systems. Two or more programs that support dynamic data exchange (DDE) can exchange information and commands.

What is DWORD? Define DWORD

A data type composed of hexadecimal data with a maximum allotted space of 4 bytes.

DVD drive

A disk storage device that uses digital video disc (DVD) technology. A DVD drive reads both CD-ROM and DVDs; however, you must have a DVD decoder to display DVD movies on your computer screen.

DVD decoder

A hardware or software component that allows a digital video disc (DVD) drive to display movies on your computer screen.

Define Duplex, What is Duplex?

A system capable of transmitting information in both directions over a communications channel.

Define Dual Boot, What is Dual Boot?

A computer configuration that can start two different operating systems.

Define Drop Folder, What is Drop Folder?

In the Macintosh environment, a folder for which you have the Make Changes permission but not the See Files or See Folders permission. You can copy files into a drop folder, but you cannot see what files and subfolders the drop folder contains.

Drive Letter

The naming convention for disk drives on IBM and compatible computers. Drives are named by letter, beginning with A, followed by a colon.

What is Drive in Computer?

An area of storage that is formatted with a file system and has a drive letter. The storage can be a floppy disk, a CD, a hard disk, or another type of disk. You can view the contents of a drive by clicking its icon in Windows Explorer or My Computer.

Define Drainstop

For Network Load Balancing, a command that disables all new traffic handling on the specified hosts. The hosts then enter draining mode to complete existing connections.
While draining, hosts remain in the cluster and stop their cluster operations when there are no more active connections. To terminate draining mode, explicitly stop cluster mode with the stop command, or restart new traffic handling with the start command. To drain connections from a specific port, use the drain command.

What is Drain?

For Network Load Balancing, a command that disables new traffic handling for the rule whose port range contains the specified port. All ports specified by the port rule are affected.

Define Drag, What is Drag?

To move an item on the screen by selecting the item and then pressing and holding down the mouse button while moving the mouse. For example, you can move a window to another location on the screen by dragging its title bar.


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Downloadable Fonts

A set of characters stored on disk and sent (downloaded) to a printer's memory when needed for printing a document. Downloadable fonts are most commonly used with laser printers and other page printers, although many dot-matrix printers can accept some of them. Downloadable fonts are also called soft fonts.

Double-Byte Characters

A set of characters in which each character is represented by two bytes. Some languages, such as Japanese, Chinese, and Korean, require double-byte character sets.

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Dots Per Inch (DPI)

The standard used to measure screen and printer resolution, expressed as the number of dots that a device can display or print per linear inch. The greater the number of dots per inch, the better the resolution.

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Domain Tree

In DNS, the inverted hierarchical tree structure that is used to index domain names.Domain trees are similar in purpose and concept to the directory trees used by computer filing systems for disk storage. For example,

DOMAIN TREE PICTURES 

when numerous files are stored on disk, directories can be used to organize the files into logical collections. When a domain tree has one or more branches, each branch can organize domain names used in the namespace into logical collections. In Active Directory, a hierarchical structure of one or more domains, connected by transitive, bidirectional trusts, that forms a contiguous namespace. Multiple domain trees may belong to the same forest.

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Domain of Origin

The parent DNS domain name that is used to root either a zone or a resource record within a zone. This name is joined to the end of unqualified or relative domain names to form a fully qualified domain name (FQDN) within the zone. In DNS Manager, the domain of origin

will correspond to Zone name as it appears in the Add Zone Wizard or the name that appears in the Parent domain name field for any resource records created within the zone.

Domain Naming Master

The domain controller assigned to control the addition or removal of domains in the forest. At any time, there can be only one domain naming master in the forest.

Domain Namespace

The database structure used by the Domain Name System (DNS).

Domain Name System (DNS)

A hierarchical, distributed database that contains mappings of DNS domain names to various types of data, such as IP addresses. DNS enables the location of computers and services by user-friendly names, and it also enables the discovery of other information stored in the database.

Domain Name

The name given by an administrator to a collection of networked computers that share a common directory. Part of the Domain Name System (DNS) naming structure, domain names consist of a sequence of name labels separated by periods.

Domain Local Group

A security or distribution group that can contain universal groups, global groups, and accounts from any domain in the domain tree or forest. A domain local group can also contain other domain local groups from its own domain. Rights and permissions can be assigned only at the domain containing the group.

Domain DFS

An implementation of DFS in which DFS topological information is stored in Active Directory. Because this information is made available on multiple domain controllers in the domain, domain DFS provides fault-tolerance for any distributed file system in the domain.

Domain Controller Locator (Locator)

An algorithm that runs in the context of the Net Logon service and that finds domain controllers on a Windows 2000 network. Locator can find domain controllers by using DNS names (for IP/DNS-compatible computers) or by using NetBIOS names (for computers that are running Windows 3.x, Windows for Workgroups, Windows NT 3.5 or later, Windows 95, or Windows 98, or it can be used on a network where IP transport is not available).

Domain Controller

In a Windows domain environment, a computer running Active Directory that manages user access to a network, which includes logging on, authentication, and access to the directory and shared resources.

What Is Domain?

Docking Station

A unit for housing a portable computer that contains a power connection, expansion slots, and connections to peripherals, such as a monitor, printer, full-sized keyboard, and mouse. The docking station turns the portable computer into a desktop computer.

DNS suffix

For DNS, a character string that represents a domain name. The DNS suffix shows where a host is located relative to the DNS root, specifying a host?s location in the DNS hierarchy. Usually, DNS suffix describes the latter portion of a DNS name, following one or more of the first labels of a DNS name.

dock

To connect a laptop or notebook computer to a docking station.

DNS Server

A service that maintains information about a portion of the Domain Name System (DNS) database and responds to and resolves DNS queries. A computer running this service is also known as a DNS server.

Distribution Group

A group that is used solely for e-mail distribution and that is not security-enabled. Distribution groups cannot be listed in discretionary access control lists (DACLs) used to define permissions on resources and objects. Distribution groups can be used only with e-mail applications (such as Microsoft Exchange) to send e-mail to collections of users. If you do not need a group for security purposes, create a distribution group instead of a security group.

Distinguished Name

A name that uniquely identifies an object by using the relative distinguished name for the object, plus the names of container objects and domains that contain the object. The distinguished name identifies the object as well as its location in a tree. Every object in Active Directory has a distinguished name. A typical distinguished name might be
CN=MyName,CN=Users,DC=Microsoft,DC=Com
This identifies the MyName user object in the microsoft.com domain.

Discretionary Access Control List (DACL)

The part of an object's security descriptor that grants or denies specific users and groups permission to access the object. Only the owner of an object can change permissions granted or denied in a DACL; thus, access to the object is at the owner's discretion.

DirectX

An extension of the Microsoft Windows operating system. DirectX technology helps games and other programs use the advanced multimedia capabilites of your hardware.

Directory Service

Both the directory information source and the service that make the information available and usable. A directory service enables the user to find an object given any one of its attributes.

Directory Partition

A contiguous subtree of the directory that forms a unit of replication. A given replica is always a replica of some directory partition. The directory always has at least three directory partitions:

• The schema, which defines the object classes and attributes contained in Active Directory.
• The configuration, which identifies the domain controllers, replication topology and other related information about the domain controllers within a specific implementation of Active Directory.
• One or more domains that contain the actual directory object data.

A domain controller always stores the partitions for the schema, configuration, and its own (and no other) domain. The schema and configuration are replicated to every domain controller in the domain tree or forest. The domain is replicated only to domain controllers for that domain. A subset of the attributes for all domain objects is replicated to the global catalog.

Direct Memory Access (DMA)

Memory access that does not involve the microprocessor. DMA is frequently used for data transfer directly between memory and a peripheral device such as a disk drive.

Direct Cable Connection

A link between the I/O ports of two computers created with a single cable rather than a modem or other interfacing devices. In most cases, a direct cable connection is made with a null modem cable.

Digital Video Disc (DVD)

A type of optical disc storage technology. A digital video disc (DVD) looks like a CD-ROM disc, but it can store greater amounts of data. DVDs are often used to store full-length movies and other multimedia content that requires large amounts of storage space.

Digital Subscriber Line (DSL)

A type of high-speed Internet connection using standard telephone wires. This is also referred to as a broadband connection.

Digital Signature Standard (DSS)

A standard that uses the Digital Signature Algorithm (DSA) for its signature algorithm and SHA-1 as its message hash algorithm. DSA is a public-key cipher that is used only to generate digital signatures and cannot be used for data encryption.

Digital Signature

A means for originators of a message, file, or other digitally encoded information to bind their identity to the information. The process of digitally signing information entails transforming the information, as well as some secret information held by the sender, into a tag called a signature. Digital signatures are used in public key environments, and they provide nonrepudiation and integrity services.

Differential Data

Saved copies of changed data that can be applied to an original volume to generate a volume shadow copy.

Differential Backup

A backup that copies files created or changed since the last normal or incremental backup. It does not mark files as having been backed up (in other words, the archive attribute is not cleared). If you are performing a combination of normal and differential backups, restoring files and folders requires that you have the last normal as well as the last differential backup.

Dictionary Attack

A method of guessing a user's password or PIN by trying every word in the dictionary until successful.

Dialog Box

A secondary window that contains buttons and various kinds of options through which you can carry out a particular command or task.

Dial-up connection

The connection to your network if you are using a device that uses the telephone network. This includes modems with a standard phone line, ISDN cards with high-speed ISDN lines, or X.25 networks.

If you are a typical user, you may have one or two dial-up connections, for example, to the Internet and to your corporate network. In a more complex server situation, multiple network modem connections might be used to implement advanced routing.

DHCP/BOOTP Relay Agent

The agent program or component responsible for relaying DHCP and BOOTP broadcast messages between a DHCP server and a client across an IP router. A DHCP relay agent supports DHCP/BOOTP message relay as defined in RFCs 1541 and 2131. The DHCP Relay Agent service is managed using the Routing and Remote Access service.

DHCP client

Any network-enabled device that supports the ability to communicate with a DHCP server for the purpose of obtaining dynamic leased IP configuration and related optional parameters information.

DFS topology

The overall logical hierarchy of the Distributed File System (DFS), including elements such as roots, links, shared folders, and replica sets, as depicted in the DFS administrative console. This is not to be confused with the DFS namespace, which is the logical view of shared resources seen by users.

DFS root

The starting point of the Distributed File System (DFS) namespace. The root is often used to refer to the namespace as a whole. A root maps to one or more root targets, each of which corresponds to a shared folder on a server.

DFS link

An element in the Distributed File System (DFS) namespace that lies below the root and maps to one or more targets, each of which corresponds to a shared folder or another DFS root.

Device Manager

An administrative tool that you can use to manage the devices on your computer. Using Device Manager, you can view and change device properties, update device drivers, configure device settings, and uninstall devices.

Device Fonts

Fonts that reside in your printer. They can be built into the printer itself or provided by a font cartridge or font card.

Device Driver

A program that allows a specific device, such as a modem, network adapter, or printer, to communicate with the operating system. Although a device might be installed on your system, Windows cannot use the device until you have installed and configured the appropriate driver.
If a device is listed in the Hardware Compatibility List (HCL), a driver is usually included with Windows. Device drivers load automatically (for all enabled devices) when a computer is started, and thereafter run invisibly.

Device Conflict

A conflict that occurs when the same system resources have been allocated to two or more devices. System resources include interrupt request (IRQ) lines, direct memory access (DMA) channels, input/output (I/O) ports, and memory addresses.

What is Device?

Any piece of equipment that can be attached to a network or computer; for example, a computer, printer, joystick, adapter, or modem card, or any other peripheral equipment. Devices normally require a device driver to function with Windows.

Details Pane

The pane in the Microsoft Management Console (MMC) that displays the details for the selected item in the console tree. The details can be a list of items or they can be administrative properties, services, and events that are acted on by a snap-in.

Destination Document

The document into which a package or a linked or embedded object is being inserted. For an embedded object, this is sometimes also called the container document.

Desktop Pattern

A design that appears across your desktop. You can create your own pattern or select a pattern provided by Windows.

Desktop

The on-screen work area on which windows, icons, menus, and dialog boxes appear.

Desired Zone

The zone in which AppleTalk network integration appears on the network.

Descendent Key

All the subkeys that appear when a key in the registry is expanded. A descendent key is the same as a subkey.

Dependent Client

For Message Queuing, a computer that requires synchronous access to a Message Queuing server to perform all standard message queuing operations, such as sending and receiving messages and creating queues.

Dependency Tree

A diagram for visualizing the dependency relationships between resources.

Dependency

A relationship of reliance between two resources that makes it necessary for them to run in the same group on the same node. For example, an application is dependent on the disks that contain its data resources.

Denial-of-service attack

An attack in which an attacker exploits a weakness or a design limitation of a network service to overload or halt the service, so that the service is not available for use. This type of attack is typically launched to prevent other users from using a network service such as a Web server or a file server.

Delegation

The ability to assign responsibility for management and administration of a portion of the namespace to another user, group, or organization.
For DNS, a name service record in the parent zone that lists the name server authoritative for the delegated zone.

Defragmentation

The process of rewriting parts of a file to contiguous sectors on a hard disk to increase the speed of access and retrieval. When files are updated, the computer tends to save these updates on the largest continuous space on the hard disk, which is often on a different sector than the other parts of the file. When files are thus fragmented, the computer must search the hard disk each time the file is opened to find all of the file's parts, which slows down response time.

Default Host

The host with the highest host priority for which a drainstop command is not in progress. After convergence, the default host handles all of the network traffic for TCP and UDP ports that are not otherwise covered by port rules.

What is Default Gateway?

A configuration item for the TCP/IP protocol that is the IP address of a directly reachable IP router. Configuring a default gateway creates a default route in the IP routing table.

Default Button

In some dialog boxes, the command button that is selected or highlighted when the dialog box is initially displayed. The default button has a bold border, indicating that it will be chosen automatically if you press ENTER. You can override a default button by clicking Cancel or another command button.

Dedicated Adapter

The network adapter that, when using multiple network adapters in each host of a Network Load Balancing cluster, handles network traffic not related to cluster operations (the traffic for individual hosts on the network). This adapter is programmed with the host's dedicated IP address.

What is Debugger?

A program designed to aid in detecting, locating, and correcting errors in another program by allowing the programmer to step through the program, examine the data, and monitor conditions such as the values of variables.