Paint like program on macbook pro?

Okay I bought my macbook a month or so ago and i remember a year ago when i went into the apple store and one of the mac people was trying to convince me to switch to a mac, he was showing me all the cool stuff it could do. I remember he took a picture and cut a person out of it, and pasted them into a different background. I know you can do this with photoshop but i don't think it was photoshop, but i can't remember the program, i think it was built into the mac. Does anybody know what it's called, or am i wrong and there isnt a program like that