 Seat maps usually indicate the basic seating layout; the numbering and lettering of the seats; and the locations of the emergency exits, lavatories, galleys, bulkheads and wings.Airlines that allow internet check-in frequently present a seat map indicating free and occupied seats to the passenger so that they select their seat from it.In addition to the published seat maps from airliners, there are a number of independent websites which also publish seat maps along with reviews of individual seats, noting the seats that are particularly good (extra legroom, quiet cabin, etc.)