The most important functions of Oracle Access Manager are single sign-on and its integration capability with different applications. I also have experience with its audit trail capability, which I find valuable. Oracle Access Manager audits all events in the system, including authentication, authorization, password resets, and user behavior. The benefits it provides to clients include enhanced security for users and applications, improved user experience through single sign-on, and scalability. As for integration, Oracle Access Manager has good integration capabilities. It supports agent-based authentication and standard protocols like OAuth, OpenID, and FEM. The integration complexity ranges from simple to medium, depending on the application.