so you mean they use lift to fly?
Yes, ridge lift, wave lift etc.
Gliding
Ridge lift rarely allows pilots to climb much higher than about above the terrain; thermals, depending on the climate and terrain, can allow climbs in excess of in flat country and much higher above mountains; wave lift has allowed a glider to reach an altitude of .
In a few countries such as the UK, gliders may continue to climb into the clouds in uncontrolled airspace,
how long do gliders stay in the air They can stay airborne for several hours. what is gliding? It is a recreational activity and competitive air sport in which pilots fly unpowered aircraft known as gliders or sailplanes using naturally occurring currents of rising air in the atmosphere to remain airborne. who created the first glider? The Germans when? In  the 1920s and 1930s how do they fly? Through air that is ascending as fast or faster than the glider itself is descending, thus gaining potential energy. what's the fastest they can go? UNANSWERABLE
wiki:14186531
Gliding [SEP] Soaring
Glider pilots can stay airborne for hours by flying through air that is ascending as fast or faster than the glider itself is descending, thus gaining potential energy. The most commonly used sources of rising air are Ridge lift rarely allows pilots to climb much higher than about above the terrain; thermals, depending on the climate and terrain, can allow climbs in excess of in flat country and much higher above mountains; wave lift has allowed a glider to reach an altitude of . In a few countries such as the UK, gliders may continue to climb into the clouds in uncontrolled airspace, but in many European countries the pilot must stop climbing before reaching the cloud base (see Visual Flight Rules).