A group is an identifier that can be used to apply permissions to a list of users associated with the identifier.

A group allows multiple users to be referenced by a single name.

For example, a company has an accounting group to identify the accounting department employees as a whole, and a payroll group to identify the payroll department employees as a whole. To define these groups, the DBA creates the groups and adds all the users in the associated departments to their respective groups. The groups can be easily maintained by adding and dropping users as they join or leave the departments.