An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human
pilot, crew, or passengers on board. UAVs were originally developed through the twentieth century
for military missions too "dull, dirty or dangerous" for humans, and by the twenty‐first, they had
become essential assets to most militaries. As control technologies improved and costs fell, their
use expanded to many non‐military applications. These include aerial photography, precision
agriculture, forest fire monitoring, river monitoring, environmental monitoring, policing and
surveillance, infrastructure inspections, smuggling, product deliveries, entertainment, and drone
racing.