A drone is basically an unnamed aircraft. They are more formally known as unmanned aerial vehicles (UAVs) or unmanned aircraft systems. A drone is a flying robot which can be controlled by the remote by using software embedded in it. UAVs are mostly used in the purpose of military. They are used in Navy, army and air force. Initially used for anti- aircraft target practice, intelligence gathering and as weapons platforms.
Not only in military purposes but these are also used in – search and rescue, surveillance, traffic monitoring, weather monitoring, firefighting, personal use, drone-based photography, videography, agriculture and also for delivery services.
Drones must have a source of power such as a battery. They require controller, which lets the operator use remote control to launch and navigate the drone. GPS system should also be installed in the drones. Some of them use sensors to detect obstacles and avoid collisions.
They are also visually positioned for landing with downwards facing cameras and ultrasonic sensors determine how close the drone is from the ground.