A passenger airline is an airline dedicated to the transport of passengers. 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.
A freight aircraft, freighter, airlifter or cargo jet is a fixed-wing aircraft that is designed or converted for the carriage of cargo rather than passengers. Such aircraft usually do not incorporate passenger amenities and generally feature one or more large doors for loading cargo. Freighters may be operated by civil passenger or cargo airlines, by private individuals or by the armed forces or individual countries.
A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat: Combat aircraft are designed to destroy enemy equipment using their own aircraft ordnance. Combat aircraft are normally developed and procured only by military forces.
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot aboard. UAVs are a component of an unmanned aircraft system (UAS); which include a UAV, a ground-based controller, and a system of communications between the two. The flight of UAVs may operate with various degrees of autonomy: either under remote control by a human operator or autonomously by onboard computers.