I found a VERY interesting link at Oracle’s website showing a lot of information on 12c:

http://www.oracle.com/webfolder/technetwork/tutorials/obe/db/12c/r1/poster/OUTPUT_poster/poster.html

It contains information on:

• DBA Views
• Performance Views
• Architecture Views
• Database Architecture
• Multitenant Architecture
• Background Processes

Enjoy!!!