Users who stake (provide funds) are ‘locking up’ their funds by depositing them onto the blockchain, which allows for it to be secure and functional. Typically, users who stake to a blockchain network earn a reward for helping to secure the network.
Staking is a very common practise with blockchains that use the Proof of Stake (PoS) consensus mechanism. After originating as a Proof of Work (PoW) platform, Ethereum became a PoS blockchain with The Merge. Many other blockchains, such as Avalanche, Cardano, and Solana, are all currently using some form of PoS.
Learn more about Ethereum staking.