Built-in Groups

The default security groups installed with the operating system. Built-in groups have been granted useful collections of rights and built-in abilities.
In most cases, built-in groups provide all the capabilities needed by a particular user. For example, if a domain user account belongs to the built-in Administrators group, logging on with that account gives a user administrative capabilities over the domain and the domain servers. To provide a needed set of capabilities to a user account, assign it to the appropriate built-in group.