contact center is a keycode enabled application on the BCM. It gives you ACD functionality only. The reporting piece is a separate keycode enable app that sends the ACD data to a separate server that hosts the RCC app. You pull data and reports from the RCC server itself. As deweyhumbolt said, it gives you all sorts of info, but can be somewhat challenging to set up. It's not terribly uncommon for the database to get errors that can cause problems running reports. Its gotten a lot better over the past few releases.
Without ACD reporting, you can do basic CDR reports but it doesn't go into as much detail as the ACD reports go into, especially on the agent side.