The Nervos Network is an open-source public blockchain ecosystem and collection of protocols.
The Nervos CKB (Common Knowledge Base) is the layer 1, proof-of-work public blockchain protocol of the Nervos Network.
The CKByte token (CKB) is the network's native token and has the following use cases:
State storage on the network: CKB represents cell capacity in bytes, and they give owners the ability to occupy a piece of the blockchain's overall global state. For example, if a user owns 1,000 CKB, he/she can create a cell with 1,000 bytes in capacity, or multiple cells that add up to 1,000 bytes in capacity. He/she can then use the 1,000 bytes to store assets, application state, or other types of common knowledge.
Miner compensation: Miners are compensated with both block rewards and transaction fees in the form of CKB tokens.
Staking rewards: CKB holders can deposit and lock their native tokens into a special contract called the NervosDAO to earn staking rewards.
More information on CKB token economics can be found here.
As at January 26th 2021, the circulating supply of CKB is ~23.7 billion and the total supply of CKB is ~30.7 billion. See here for a chart representing the circulating and total supply of CKB.