It’s an emulsification of water and a mix of cheddar cheeses with preservatives, stabilizers, and an emulsifier (obviously) added. It has some culinary applications but the real reason it’s made that way is it lets Kraft get away with selling less cheese overall for the same price as a block of 100% cheddar of the same volume by marketing it as a different type of cheese (American) rather than what it actually is (watered down cheddar).