The term "American Cheese" has been used to describe many different cheeses over the past few centuries. In the early 1800's it was used to describe American versions of cheddar. Now, American cheese is used to describe processed cheese.
The manufacturing process of processed American cheese is quite different than that of other cheeses. Ingredients are mixed, heated, and then poured into molds to cool down.
American processed cheese traditionally used cheese scraps of cheddar or colby as part of the ingredients, but currently most do not. One popular brand of American cheese has 15 ingredients in its cheese, while most cheeses have about three or four ingredients.
Where to buy:
We'd suggest you didn't buy American processed cheese. But if you insist, it's in almost every grocery store.