The Core 101 tutorials are designed to give you the best core grounding of training to help you make the most of the app you want to learn.
Typically you could consider this a beginner + level, a great place to start and often one that will allow you to fully understand all the core concepts of that application.
The "Core 101" or "201" etc refers to the level of training of our video tutorials.
The CS4 refers to the Adobe version of their software. e.g The current version of Illustrator is called Illustrator CS4.
