First-come, first-served

First come, first served (sometimes first-come, first-served or simply FCFS) is a service policy where by the requests of customers or clients are attended to in the order that they arrived, without other biases or preferences. The policy can be employed when processing sales orders, in determining restaurant seating, or on a taxi stand, for example.

Festival seating (also known as general seating and stadium seating) is seating done on a FCFS basis. See Riverfront Coliseum for details on a December 1979 disaster involving "festival seating" at a concert by The Who in Cincinnati, Ohio.

The practice is also becoming common among low-cost airlines in Europe where seats cannot be reserved either in advance or at check-in. These airlines allow passengers to board in small groups based upon their order of check-in and sit in whatever seat on the aircraft they wish to. On the basis of first come, first served, the earlier you check-in the earlier you board the aircraft to get the seat you want.

Southwest Airlines and major European low-cost airlines such as easyJet also apply first come, first served seating. Passengers are sequentially (on a first come, first served basis) assigned into one of three "boarding groups". The passengers then are boarded onto the plane in group-order.

The phrase is often but erroneously stated as "first come, first serve" (instead of "served"). This is an error because the phrase abbreviates the sentence "The first to come is the first to be served."

See FIFO (first-in, first-out) for the technical concept of the same policy.
Source: http://en.wikipedia.org/wiki/First-come,_first-served