Operations are processed by a set of validators, each with a specific amount of stake from SUI token holders. A validator's share of the total stake on the network determines each validator’s voting power for processing transactions. Staking SUI implies that the SUI tokens are locked for a fixed duration, called an epoch. SUI token holders are free to withdraw their SUI or to move their stake to a new validator when an epoch changes.
Validators provide a service to Sui by operating and securing the network. In exchange, they are compensated with commissions from staking rewards. In the early phases of the network, staking rewards are made up of stake subsidies plus gas fees. The subsidies are necessary as gas fees will likely be relatively low. In the long run, the entirety of rewards will be gas fees.