The circulating supply is the total number of coins/tokens of a specific cryptocurrency that are publicly available and circulating in the market.
Understanding the Term
Over time, a circulating supply can increase as new coins are developed through mining. A centralized token supply can also be increased by the developers via instantaneous minting.
However, the circulating supply can also decrease in two ways. The first being, on purpose by burning, which is the process of permanently taking cryptocurrency coins or tokens out of circulation. The other is by accident, for instance, when coins are being sent to an irrecoverable address or even when losing access to a wallet where funds are stored.
Circulating supply should not be confused with the total supply, which is the total amount of coins in existence, excluding those intentionally burnt.