Drones are technically known as Unmanned Aerial Vehicles (UAV) or Remotely Piloted Aerial Systems (RPAS). The drone is similar to that of a helicopter but the primary difference is the necessity of a helicopter to have a manned pilot. A drone is unmanned, meaning there is no actual pilot in a drone. It is controlled by a pilot from the ground to fly around areas that can’t be reached easily by manned aircrafts.So that somewhat answers your "how do drones work " question ?Read on for more boring stuff - if you are really into this kinda stuff.
Drones are used mostly for two things: first, for surveillance purposes as it can capture and transmit live images of what is happening on the ground; and second, for reconnaissance since it can be armed with small equipment or bombs and missiles. It can stay in the sky hovering or flying over the target area for a prolonged period of time, which is why it is a great backup support to military troops when they are unable to manually fly over a hostile area.
A good point to know about a drone is it can also be used by citizens — not just by the military. In most sporting events that has a wide area for playing, like in football or soccer, cameras can be attached to a drone, thereby giving aerial views of the playing field and surrounding stadium during the game. Of course, when additional weight is added to the drone, it can lessen its aerial capability; hence, having a good number of motors will help the elevation that the UAV can achieve.
Unlike helicopters that have one or two propellers, drones use several propellers, which is good especially if one malfunctions; the other propellers can still work in place. A drone uses removable batteries that make rotors and propellers work. The battery can last at least 12 minutes in the air but some manufacturers offer extra batteries so its power extends to 25 minutes.
How Drones Fly:
Although drones are unmanned, a pilot on the ground uses a wireless controller or remote control device to launch the drone from the ground up in the air, to navigate it while flying, and to land it safely. The remote control can be in the form of a gamepad, a smartphone, or something tablet-shaped. The drones are normally operated through a radio wave that has a frequency of 2.4 GHz ( the frequency on wireless mice and keyboards ) , but can also be controlled via a WiFi connection that still relays the same 2.4 GHz spectrum.
Just like in smartphones, drones are implanted with a Global Positioning System (GPS) chip to dispatch its location to the controller and to keep a record of its activities from where it took off, in case it landed without the controller’s assistance. While in the air, the GPS implanted in the drone will guide the drone in maintaining its axes even when countering strong winds.
The UAV also uses gyroscopes which help in maintaining its balance. It also has onboard sensors that keep it in the air; a device called altimeter indicates the height of the drone from the ground level or sea level at the present time.
Landing of Drones:
Just like helicopters, drones are designed to land slowly, but because of its propellers and rotors, landing a drone can be quite tricky. The rotors form a vacuum that pulls down the UAV at a greater force than needed. If the land it is hovering at has no GPS access, the drone can create a map of the land with its onboard ultrasonic sensors and determine a safe area to land on — even on its own .( Part 2 - Top drone brands )