What are they? Also known as Unmanned Aerial Vehicles (UAVs), drones are aircraft without a human pilot on board. They can either fly autonomously or be operated by remote control.

What are they used for? Militaries around the world have used drones since the early 1980s for surveillance missions and airstrikes, mainly because they’re considered cheaper, safer, and more accurate than using human aircrews. The US Air Force is estimated to have around 7,500 drones, which is almost a third of its total number of aircraft. But drones have a huge array of other applications besides just acting as a quick and easy way of eliminating members of the Taliban. They’re used to survey crops, film Hollywood blockbusters, deliver medical supplies in disaster zones, and prevent wildlife poaching. Amazon even plans to develop a fleet that will deliver packages to your doorstep, and flying toy drones have also become hugely popular amongst hobbyists.

Any drawbacks? There are big legal and ethical questions surrounding the use of drones in warfare, such as who’s responsible for an autonomous aircraft that wrongly targets a school bus instead of a tank? Toy drones are also becoming a worry for air safety officials. In January, flights in and out of Dubai airport were halted for several hours because a drone strayed dangerously close to vital flight paths. And then there are the potential privacy concerns of having a drone with an onboard camera buzzing around your bedroom window.