Fixed-wing drones look like normal airplanes, where the wings provide the lift instead of rotors- making them very efficient. These drones usually use fuel instead of electricity, allowing them to glide in the air for more than 16 hours.
Since these drones are usually much larger, and because of their design, they need to take off and land on runways just as airplanes do. Fixed-wing UAVs are used by the military to carry out strikes, by scientists to carry large amounts of equipment and even by nonprofits to deliver food and other goods to areas that are hard to reach.