RVR,
Yes, CPS main function is file versioning basically. The note about two machines needed is that you have to set up your main CPS server (CMS server) which has the UI Console. Consider this you BE Media server for comparison. Then from the CPS console, you will see an option for Servers. Right click on that, and select a server to push the remote agent (CPA (continuous protection agent) in the case of CPS) to.
Keep in mind, your main CPS server must be Windows 2003 due the requirement of the destination folder (where all information is protected to) A CPS server cannot protect itself, due to the obvious viscious circle that would result as new data is written. To protect the CPS server, Backup Exec is used to protect the server itself (if seperate from BE) as well as all the data that CPS has protected from other servers.