What is Gliding?
Gliding is engineless free-flight. Once a glider is launched, by aerotow or winch-launch, it will descend at a given rate. However, if rising air is encountered, flight times can be extended. Try thinking about walking down an escalator that’s traveling upwards…
Through skilful use of rising air (generally known as thermals, or just ‘lift’) glider pilots can fly for hours off one launch and travel hundreds of kms from the launch site before returning. Much more information can be found on the British Gliding Association site.