Resting

All creatures, including player characters, can take rests to restore hit points and other features. You can't overlap rests of the same kind. For example, you can take one or more short rests during a long rest, but you can't start a short rest during another a short rest. You can end a rest at any time, however.

Short Rest

A short rest takes 1 hour. It consists of light activity, such as treating wounds, meditating, or standing guard. You can't take a short rest while unconscious unless another creature tends to you. If you take any damage during a short rest, you must restart. At the end of a short rest, you regain each resource that recharges on a short rest and that was expended before the rest began. It is also acceptable to gain the full benefits of the Heal action as many times as you like, as long as someone is capable of healing you and succeeding on the check.

Long Rest

A long rest takes 8 hours. It consists of light activity and sleeping. If you take any damage during a long rest, you must restart. At the end of a long rest, you experience the following effects:

You regain all your hit points and hit dice.
If you sleep for 6 hours or more, you lose one level of exhaustion (if you had any).
You regain each resource that recharges on a long rest and that was expended before the rest began.
You can't begin another long rest until at least 8 hours have passed.

Sleeping

If you go 24 hours without sleeping (i.e., being unconscious) for at least 4 of those hours, you gain 1 level of exhaustion. You can gain exhaustion in this way only once every 24 hours.