Staking involves freezing token on your address. During this time, tokens cannot be traded - they are, in a way, locked in the stake pool. In return, the staker receives a reward.
The rewards are the same tokens as that delegated - AMLT
The more tokens you freeze and the longer it lasts, the greater is the reward.
The staking rewards are usually distributed on 10th day of each month.
You can order a withdrawal/return of delegated tokens and stop staking at any time. It's important that only tokens staked for calendar month can participate in reward.