A drone, in a technological context, is an unmanned aircraft.
Drones are more formally known as unmanned aerial vehicles (UAV). Essentially, a drone is a flying robot.
The aircraft may be remotely controlled or can fly autonomously through software-controlled flight plans in their embedded systems working in conjunction with GPS.
UAVs have most often been associated with the military but they are also used for search and rescue, surveillance, traffic monitoring, weather monitoring and firefighting, among other things.
More recently, the unmanned aircraft have come into consideration for a number of commercial applications.
Multiple Drones working together.
In late 2013, Amazon announced a plan to use drones for delivery in the not-too-distant future. The service, known as Amazon Prime Air, is expected to deliver orders inside a 10-mile radius of a fulfillment center within 30 minutes.
In late 2012 Chris Anderson, Editor-In-Chief of Wired magazine, retired to dedicate himself to his personal drones company, 3D Robotics. Personal drones are currently a hobbyist’s item most often used for aerial photography, but the market and potential applications are both expected to expand rapidly.
A police Inspector using drone for Remote Surveillance
A Documentary on Robots That Fly
In the United States, the Federal Aviation Administration (FAA) is developing regulations for the operation of unmanned aircraft.
Where does the term drone come from?
When unmanned flying vehicles were first introduced to the U.S. military, the ability to control them from afar wasnt very sophisticated. So the first drones flew along pre-set paths, operating off an internal navigation system. This led to servicemen informally referring to any machine that flew without human control a "drone," and Germany still has some like this in service today. That said, the "not being controlled by a human" part of the definition has since been lost to everyday use.
What exactly are drones?
"Drone" as a category refers to any unmanned, remotely piloted flying craft, ranging from something as small as a radio-controlled toy helicopter to the 32,000-pound, $104 million Global Hawk. If it flies and its controlled by a pilot on the ground, it fits under the everyday-language definition of drone.
Wait, does that mean model airplanes are drones?
Almost! Actually, under the law as it stands, any unmanned, remotely piloted vehicle in the United States flown for hobby or recreational purposes is a model airplane, thanks to the 2012 FAA re-authorization act. In 2015, the FAA will suggest new, drone-specific regulations, at which point model airplane law and drone law will probably diverge. Until then, though, all small drones used by private citizens in the U.S. are legally model airplanes.
So is the military using model airplanes?
No. The military is not considered a private citizen, so it plays by different rules, and uses different terminology.
Okay, so what terms does the military use?
The military has described drones, variously, as Unmanned Aerial Vehicles (UAVs), Remotely Piloted Vehicles (RPVs), Unmanned Aerial Systems (UASs), and Remotely Piloted Systems. (The FAA uses some of these terms, too.) The difference between UAV/RPV and UAS/RPS is that the former terms refer to the vehicle itself, and the latter terms describe the vehicle as well as the pilot and support staff. These are useful distinctions for specialists, but not for regular people.
Drones can be used for a lot of civilian use cases as well
Some More Civilian Uses of Drone Robots are
E-Commerce Goods Delivery at customers Door steps