A supermarket is a full-size grocery store, with a nearly complete array of usual foodstuffs for sale. Supermarkets normally also include an inventory of disposable household goods.

Large stores which specialize only in a particular class of food, such as dairy products or produce, are classified according to their specialties, and not as supermarkets. A drugstore can be combined with a supermarket if a major part of it is dedicated to foodstuffs, and it offers a variety of food sufficient for a normal person's regular shopping. Big-box stores that sell large quantities of general merchandise in addition to supermarket offerings are classified as hypermarkets.

Breadth of food selection matters as well as size. A large produce-only store remains a greengrocer, while substantial general merchandise can place a store within the hypermarket definition.