Staking is a process of contribute your holding coins to the blockchain, so it can be used for the transaction verification process, in exchange, you get a reward over time.
It's only available in §202109171229 Proof-of-Stake blockchains.
The amount of rewards are varies between cryptocurrencies, and some cryptocurrency also have rewards in different type of token.
The benefits of staking is, you earn a passive income from your holdings without the need of trading.
The risk of staking is, once you stake your holdings, it can't be moved (sell or transfer), so, if the price drop, the earned income might not enough to cover the loss.