A supermarket is a self-services store. It is the important type of retail ( 零售 ) by combining self-service with low prices. An average supermarket handles ( 买卖 ) thousands of edible things including vegetables, meat, fresh fruits, canned groceries, bakery items, frozen foods and dairy products. Some also carry items such as seafood and liquor. Non-edible things in supermarkets include household cleaners, paper products, health and beauty aids, and house wares. The markets are located in shopping centers, business centers, neighborhood areas and along highways. Self-service stores were set up in the US in the early 20th century. The American merchant ( 商人 ) Michael Cullen opened the first supermarket, which he called King Kullen in 1930, in New York City. Supermarkets grow rapidly. Wider ownership of cars and home refrigerators and the appearance of packaged groceries contributed to the popularity ( 普及 ) of supermarkets. Moreover, the general consumer appeal of the supermarket concept—large size, self-service, variety of goods, one-stop shopping, and low prices—ensured their growth. Today, supermarkets are operated by chains of various sizes and by independent ( 独立的 ) owners. The supermarket concept is gaining increasing popularity throughout the world.