Magic is a CCG/TCG. It's similar, but much different.

In Magic, you buy/trade for cards to build a deck (with restrictions) outside of the game. Then you play with your completed decks. In the deck building game genre, each game comes with all the cards you need to play, and you build your deck while playing. You have your starting cards (which is anywhere from 10-15 cards) that make up your deck, then you buy or gain other cards to improve it. Expansions help with the variation, but generally speaking, you really only have to buy a base set in order to play the game.

For the record though, I've been playing Magic since Ravnica was released. I'm not as big a player anymore because of time and money, but I still like to play EDH (Commander) with friends every now and then.

I haven't played Dominion yet, even though it's supposedly the grandfather of deck building games. I'm not sure if my friend owns it, but if he does, I hope to play it soon. I'm also interested in Ascension (which has a professional Magic player on it's creation team).