An unmanned aerial vehicle (UAV) is an aircraft that carries no human pilot or passengers. UAVs sometimes people call it drones, which can be fully or partially autonomous but are more often  remotely controlled by a pilot. 

Unmanned aerial vehicles (UAVs) are the robotic devices that can fly without the help of a human pilot. 

UAV have outstanding advantages over manned aircraft, and have evolved into a weapon for modern warfare, with their consumable properties constantly strengthened.