What is the difference with a stiff snowboard and a flexible, thin snowboard?

Good question. More flexible boards are a little easier for beginners because of "torsional flex." For instance, if you lift the toe of your front (and you're left foot forward "regular foot") you want the board to flex and turn left so you can stop. If a board is too stiff it will be harder to control your edges and that's the name of the game. Once your more advanced, free style riders ("park rats") like a softer board so they can do nose presses and tail presses on boxes and rails. Softer boards are a little more forgiving on landings if you don't get your spins quite all the way around. Free riders like a stiffer board so their nose doesn't chatter at high speeds and so it doesn't flop like a wet noodle when you land big cliffs. In my mind the best boards are the ones that are as soft as they can be (because they're more fun) without being so soft that the nose chatters or they crumble under cliffs. This answer is courtesy of Blank Snowboards. Check us out at www.blanksnowboards.com How I explained above is how we make our high quality boards.

The flexible ones will be easier for biginners to learn to link and carve turns. Freestylers like a little flex (but not too much) in their board so they can "pop" the board and do tricks. The stiff ones will hold their lines better and go faster. If you get a board the is too flexible, in no time you'll out grow it and want one that is not so flexible.