Tezos, which was launched in 2018, is a decentralized blockchain network that can upgrade itself through a consensus protocol.
Token holders can participate in deciding what upgrades and changes are made to the blockchain, as well as in validating transactions and publishing these to the blockchain. A consensus is reached via a Liquid Proof of Stake mechanism where token holders place their stakes to make decisions on the state of the blockchain.
With Tezos, the process of validating transactions and publishing these to the blockchain is called "Baking". Bakers who are given the privilege of validating a block are rewarded with tez.
Because there are certain requirements to be a Baker, participants may also opt to delegate their validation rights to a Baker by staking. Bakers who receive tez from validating a block are responsible for distributing the tez to stakeholders that delegated validation rights to them.