A cracker is a type of biscuit that developed from military hardtack and nautical ship biscuits.
The holes in crackers are called "docking" holes. The holes are placed in the dough to stop air pockets from forming in the cracker while baking.
In U.S. English, the name "cracker" is most often applied to flat biscuits with a savoury, salty flavour, in distinction from a "cookie," which may be similar to a "cracker" in appearance and texture, but has a sweet flavour. Crackers may be further distinguished from cookies by the manner in which they are made. Crackers are made by layering dough and cookies are made in any manner a cake would be made. Crackers sometimes have cheese or spices as ingredients. Some crackers are salted, flour products.
Brands including Captain's Wafers, Club Crackers, Town House Crackers, Ritz Crackers, Cream crackers and Water biscuits are used spread with cheese, pâté, or mousse.
Saltine and oyster crackers are often used in or served with soup.