ESF uses external security managers to make security decisions. Because those managers are not part of ESF, administrative changes to security information - changes to the security information for users, groups, or resources - are often made directly to the managers without any interaction with ESF. In some cases, it's necessary to notify ESF of these changes, so it (and its ESM Modules) can flush any cached results and update any internal information regarding the updated entity.
The ESF Administrative Update Notification request is part of the ESF API. It lets the calling environment notify ESF that one or more administrative changes have been made in an external security manager, so it should update any internal information that may be affected.