Unmanned aerial vehicle
An unmanned aerial vehicle (UAV), or unmanned aircraft system (UAS), commonly known as an aerial drone or simply drone, is an aircraft with no human pilot, crew, or passengers on board, which instead is either autonomous or controlled remotely. UAVs were originally developed through the twentieth century for military missions too "dull, dirty or dangerous" for humans, and by the twenty-first had become essential assets to most militaries.