The Authorize module defines the plug that handles the actual authorization of a request

The Controller module provides functions that are to be used by controllers in your application. These may not strictly be controllers, but they are for the part of your application that will handle the request, and trigger the authorisation

The Enforcer module defines a plug which enforces that a request has been authorized. This should be used in your applications router in whatever pipeline you want verified

The Policy module provides very little functionality, but is key to the way in which Rampart works. Any user defined policy must use this module, which allows Rampart to find it when your application starts