Not the same at all. Nothing I could describe in 10 words or less. How much experience did you have with Edgecam? How well did it work for you?
Mastercam has a set of rules for doing things (Selecting things, Setting values, Creating geometry, Etc...). Once you understand the rules you'll find it's fairly consistent.
If your completely new to the Mastercam Environment, I would suggest this CD. It will get you pointed in the right direction.