Interior of an Amtrak Superliner Sightseer lounge car.
A lounge car (sometimes referred to as a buffet lounge, buffet car or club car) is a type of passenger car on a train, where riders can purchase food and drinks.  The car may feature large windows and comfortable seating to create a relaxing diversion from standard coach or dining options. In earlier times (and especially on the "name" trains), a lounge car was more likely to have a small kitchen, or grill and a limited menu. Food was prepared to order and often cooked, though items such as club sandwiches would have usually been part of the offerings. The cars were often operated by the Pullman Company, and in other cases by the railroad directly as part of the dining car department (on the Atchison, Topeka and Santa Fe Railway the Fred Harvey Company manned the food concession).
Lounge cars operated by Pullman were exclusively for the use of sleeping car passengers, while those operated by the railroad were available to coach as well as first-class travelers. Buffet lounge cars were often found in trains which did not offer full dining car service. On other trains they supplemented the diner and offered sandwiches, burgers and short orders at times when the diner was not serving; e.g. mid-afternoon and late night. To qualify as a buffet lounge the car had to offer both food and drink service. Buffet lounges should not be confused with snack or grill cars which did not offer a full range of libations.
In Britain, luxury lounge cars are known as "Pullman" cars, after the American Pullman Company.