On the enterprise security front, authentication is the battle but authorization is the war.
Authentication lets companies determine who is accessing the resources on their networks.
Validating a user's identity is only the first step. It's even more important to determine what users are allowed to do once they get in. Operating system-based authorization services let you use access controls to protect resources. For example, you could use operating system-based access controls to declare that only the marketing group can use the expensive color printer. They are designed for decentralized operation from the resource up.