Flight attendants or cabin crew (also known as stewards/stewardesses, air hosts/hostesses) are members of an aircrew

Aircrew

Aircrew are the personnel who operate an aircraft while in flight. The composition of the crew depends on the type of aircraft as well as the purpose of the flight.-Civilian:*Aviator** Pilot-in-command** First officer** Second officer** Third officer...

 employed by airline

Airline

An airline provides air transport services for traveling passengers and freight. Airlines lease or own their aircraft with which to supply these services and may form partnerships or alliances with other airlines for mutual benefit...

s primarily to ensure the safety and comfort of passenger

Passenger

A passenger is a term broadly used to describe any person who travels in a vehicle, but bears little or no responsibility for the tasks required for that vehicle to arrive at its destination....

s aboard commercial flights

Passenger airline

A passenger airline is an airline dedicated to the transport of passengers. Cf. cargo airline. Passenger airlines usually operate a fleet of passenger aircraft which, rather than being owned outright, are usually leased from commercial aircraft sales and leasing companies such as GECAS and...

, on select business jet

Business jet

Business jet, private jet or, colloquially, bizjet is a term describing a jet aircraft, usually of smaller size, designed for transporting groups of up to 19 business people or wealthy individuals...

 aircraft, and on some military aircraft.
The role of a flight attendant derives from that of similar positions on passenger ships or passenger trains, but it has more direct involvement with passengers because of the confined quarters and often longer travel times on aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

.