Landing is the last part of a flight, where a flying animal, aircraft, or spacecraft returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing" and "touchdown" as well. A normal aircraft flight would include several parts of flight including taxi, takeoff, climb, cruise, descent and landing. This article describes the last portion of flight as the plane, bird, or rocket touches the ground. Landing occurs after descent.

While inflight the four major forces acting on the object are; lift, thrust, gravity and drag. Flying is accomplished by generating enough lift to offset gravity to stay in the air. See the picture of the wing describing the four forces.

To land the airspeed and the rate of descent are reduced to where the object descends at a slow enough rate to allow for a gentle touch down.

Each different type of flying object generates lift in a different manner. Airplanes, birds and flying insects use a wing. A bird generates thrust and lift by flapping its wings, and aircraft generate thrust with some form of an engine. The air passing over the wing of an aircraft generates lift. A helicopter uses rotary wings to generate lift and changes the angle of the rotor to generate thrust. Rockets or Vertical Jet engines are also commonly used on speciality aircraft to generate Lift. Air balloons use a lighter than air gas to generate buoyancy or lift.

The term landing is also applied to people or objects descending to the ground using a parachute. These objects are considered to be in a controlled descent instead of actually flying. A parachute works by capturing air inducing enough drag that the object that is falling hits the ground at a relatively slow speed. There are many examples of parachutes in nature including the seeds of a dandelion. People who intentially land using a parachute are called parachutists.

Sometimes a safe landing is accomplished by using multiple forms of lift, thrust and dampening systems. The lunar lander used a rocket, landing gear and the legs of the astronauts to land on the moon. Several Soviet rockets including the Soyuz have used parachutes and to dampen the landing on earth.

Aircraft usually land at an airport on a firm runway or helicopter landing pad, generally constructed of asphalt concrete, concrete, gravel or grass. Aircraft equipped with pontoons with are able to land on water. Aircraft also sometimes uses skis to land on snow or ice.

For aircraft, landing is accomplished by slowing down and descending to the runway. This speed reduction is accomplished by reducing thrust and/or inducing a greater amount of drag using flaps, landing gear or speed brakes. As the plane approaches the ground the pilot will execute a flare to execute a gentle landing.