On Windows based enterprise with Active Directory it is very usual to use AD groups to reinforce access lists/authentication within enterprise applications/services/databases and mashups.
If you’re lost at why you cannot access some application to take a look at, and that application uses integrated security, you’re better off knowing which AD group your username is associated with…
On the OS command prompt type in this handy command:
NET USER “username” /DOMAIN
where “username” should be replaced with your windows login.