A business jet, private jet, or bizjet, or simply B.J., is a jet aircraft designed for transporting small groups of people. Business jets may be adapted for other roles, such as the evacuation of casualties or express parcel deliveries, and some are used by public bodies, government officials or the armed forces.
Almost all production business jets, such as General Dynamics' Gulfstream and the Gates Lear Jet (now built by Bombardier), have had two or three engines, though the Jetstar, an early business jet, had four. Advances in engine reliability and power have rendered four-engine designs obsolete, and only Dassault Aviation still builds three-engine models (in the Falcon line). The emerging market for so-called "very light jets" and "personal jets", has seen the introduction (at least on paper) of several single-engine designs as well.