Staking is the process of holding (storing) cryptocurrency to ensure operations in the blockchain. It is closely related to the Proof-of-Stake (PoS).
In order for the validator to participate in the creation and verification of blocks, he must block a certain stake of coins — a stake. Thus, unscrupulous validators are excluded from the network: if they fail to fulfill their obligations, the validator loses the blocked amount. The validator receives a reward for the work performed.