Maximum supply
The maximum amount of ADA supply is 45 billion. By protocol code there will never be more than 45,000,000,000 ADA tokens created.
Total supply
Cardano's total supply is derived from Maximum Supply (45B) minus the Reserve Supply.
Reserves
The reserve consists of ADA not yet added to circulation. ADA in the Reserve Supply is to be distributed as rewards to stakeholders and into the treasury each epoch. In the year 2148, the Cardano Reserve Supply is depleted, and rewards will come from transaction fees.
Total Live Stake
Live stake is the amount of ADA staked as of right now.
Total Active Stake
Active stake is the amount of staked ADA measured with a snapshot taken two epochs ago. This number lays the foundation for calculating stake rewards.
Total Staked
The total percent of ADA currently staked in Cardano. Found by dividing Total Live Stake by Total Supply.