Technology used to put people to sleep for a long time, while slowing the aging process.
Cryo Stasis involves putting an individual into a hibernation like sleep, while placing them in an enclosed cold environments. They are usually fed chemicals and/or gasses that slow down their biological functions and stop frost bite while they sleep.
It was invented for long periods of travel through space, but it was also used by some in place of prison cells.
Capsule for this, are usually called Cryo Pods.
Hypersleep is similar, but the individual in not placed in freezing temperatures.