A drone is an aircraft which is operated remotely or piloted using an autonomous system. By nature, all drones are unmanned because a pilot is not present in the aircraft, but people occasionally use the redundancy “unmanned drone” to describe such aircraft, or to differentiate between an aircraft and the type of worker bee known as a “drone.” Drones are primarily in usage among the world's militaries, where they perform a variety of tasks, and they are also utilized by law enforcement agencies. Some other uses for drones have evolved as well, such as scientific research, where an unmanned drone can do the work of a human pilot more efficiently and cheaply.
The earliest drones were developed around 1916, an age when people were experimenting with aircraft considerably. Since then, the technology behind such planes has vastly improved. Modern drones have very sophisticated systems behind them, and they can perform a wide variety of tasks, from basic surveillance of a contested border to precision drops of supplies and propaganda.
A drone can work in one of two ways. Either a pilot operates the aircraft remotely, either using line of sight communication with the plane or inside a communications center which can be anywhere in the world, or the plane is programmed with information which allows it to fly on its own. In this case, the plane may be given a specific flight route to follow, or it may be set loose and given a particular target, with the plane using its programming to reach the destination. An unmanned drone can also have sophisticated programming which allows the plane's computer to make snap judgments in the air to respond to emerging situations, such as enemy fire.
The big advantage to using an unmanned drone as opposed to a manned aircraft is that the drone can be sent into dangerous locations. Many militaries believe that the lives of their pilots are far more important than a single plane, and they may use drones to gain reconnaissance data in a war zone, contested area, or other dangerous location without risking someone's life to get the data. Drones can also be used for airstrikes and other more aggressive activities. Training a drone pilot tends to be less costly than training a real pilot, and drone pilots can work on home soil in air bases, rather than being dispatched around the world. The pilot of a drone also does not receive combat pay, because he or she is never in combat.
Using drones has not been without controversy. Some people have suggested that sending an unmanned drone out to do the military's dirty work distances people from the real business of war, increasing the risk of making careless airstrikes which result in civilian casualties. Drones are also very expensive, making the occasional loss a rather costly event, and for some people, they evoke unpleasant futuristic associations with robots. Others have said that drones can never do the work of manned aircraft with skilled pilots, while some military pilots have complained that drones spend far more time in the air than they do, taking the fun out of military aviation.