Well, it has all of the dice rolly elements most games have, but what the system different are the aspects. Aspects are little one-five word descriptions of your character that give you bonus dice on appropriate rolls. So, if you've an aspect called "Really hates Chuck", then you can get bonus dice when you're doing something to mess with Chuck.
But, you're enemies can also use aspects against you. Continuing to use "Really hates Chuck" as an example, you're enemies can use your aspect to get bonus dice if they want you to go against Chuck, even if it's against your best interests. There's more to it than that, but that's kind of the gist.
I'd really recommend two other Fate games. Spirit of the Century, my favorite, is a pulp game, and Houses of the Blooded, an anti D&D, that's also really good.