Skydiving, is a method of transiting from a high point in the atmosphere to the surface of Earth with the aid of gravity, involving the control of speed during the descent using a parachute or parachutes.

For human skydiving, it may involve a phase of more or less free-falling (the skydiving segment) which is a period when the parachute has not yet been deployed and the body gradually accelerates to terminal velocity.

For cargo parachuting, the parachute descent may begin immediately, such as a parachute-airdrop in the lower atmosphere of Earth, or be significantly delayed, such as in a planetary atmosphere where an object is descending "under parachute" following atmospheric entry from space, and may begin only after the hypersonic entry phase and initial deceleration that occurs due to friction with the thin upper atmosphere.