Help out a newbie!

[JenBean]

I just purchased a playstation 2 for my son for his birthday. For his first game, I bought Blue's Clues because it seemed suitable for a three year old. Anyway, since he is 3, I really want to make a back-up to use so he doesn't ruin the original. I downloaded what I believe to be the game, however when I wrote it to my cd, it wrote really quick.... how do I know if I am downloading the full game, or just part of it? And, what is a patch?