A restaurant is a retail establishment that serves prepared food to customers. Service is generally for eating on premises, though the term has been used to describe take-out establishments and food delivery services. The term covers many types of venues and a diversity of styles of cuisine and service. A restaurant owner is called a restaurateur; both words derive from the French verb restaurer, meaning to restore. Restaurants range from unpretentious lunching or dining places catering to people working nearby, with simple food served in simple settings at low prices, to expensive establishments serving refined food and wines in a formal setting. In the former case, customers usually wear casual clothing. In the latter case, depending on culture and local traditions, customers might wear semi-casual, semi-formal, or even in rare cases formal wear. Typically, customers sit at tables, their orders are taken by a waiter, who brings the food when it is ready, and the customers pay the bill before leaving. In finer restaurants there will be a host or hostess or even a maître d'hôtel to welcome customers and to seat them. Other staff waiting on customers include busboys and sommeliers. Restaurants often specialize in certain types of food or present a certain unifying, and often entertaining, theme. For example, there are seafood restaurants, vegetarian restaurants or ethnic restaurants. Generally speaking, restaurants selling "local" food are simply called restaurants, while restaurants selling food of foreign origin are called accordingly, for example, a Chinese, Italian, greek,mexican,japanese,indonesian,turkish,dutch,fast food, buffet restaurant and a French restaurant. As of 2006, there are approximately 215,000 full-service restaurants in the United States, accounting for $298 billion, and approximately 250,000 limited-service (fast food) restaurants, accounting for $260 billion, according to the 2006 U.S. Industry & Market Outlook by Barnes Reports.