Mozzarella is, at least theoretically, about the same texture throughout the whole sphere. Burrata is a balloon of harder, chewier mozzarella surrounding a softer, runnier mozzarella, so that when you bite into it you get an explosion of both textures of cheese. It does not keep well at all because it dries out, but a really good burrata is, bar none, the best cheese I've ever had. (That said, in this country you're only going to get half-good burrata because it doesn't keep and it doesn't travel and it ought to be made of buffalo milk and this cheese in its natural habitat is, all by itself, almost reason enough to move to Italy, but a half-good burrata is still better than most other cheeses.) Should you find some, expect to pay a ridiculous amount, eat it the same day, and then realize that they were undercharging.

I paid $8 for 3/4 lb. of burrata about halfway up the quality scale last week. WORTH IT SO HARD.