What is the Global Catalog?

If you are working with Active Directory in Windows Server 2000, the Global Catalog (GC) plays an important role in directory searches.

A Global Catalog server stores a partial copy of objects from all domains in the forest. This allows users and applications to search for information without contacting every domain individually.

The Global Catalog contains commonly used attributes for directory objects. It is also used during user logon and directory searches.

Administrators can configure Global Catalog servers through Active Directory Sites and Services.

This is good to know when troubleshooting Active Directory searches or authentication issues.