PhotoshopCS is version 8. In my opinion it is much better then version 7. I would argue that it's not an "essential" upgrade if you have version 7 but if you are to buy a new package then version 8 (CS) would be better. The Creative Suite wording is the way in which PS integrates with the other Adobe products. Primarily through a web based Java/Tomcat program called Version Cue. It allows for collaberative work on projects within work groups.