What is Baking Tezos ?

Tezos uses a proof-of-stake protocol. This mechanism secures the network, like the known mining with Bitcoin.

The difference between mining and baking is that your power does depend on the amount of Tez you hold not on the hardware power you have.

Like with mining you will be rewarded to participate in the proof-of stake mechanism with Tezos tokens depending on the amount you bake or delegate.