The overall total possible amount of a token that will ever exist or be created.
Maximum supply is the highest possible amount of a cryptocurrency token or coin that will ever exist. This number is the overall total, meaning that it cannot be added to. Thus, whenever this supply is exhausted, traders will not be able to mine more from the network and will have to rely on exchanging with other traders. The concept relies on rarity which exists to protect the coin so that it does not become irrelevant overtime and can increase fairly predictably in value. Most crypto coins have a maximum supply. Bitcoin’s maximum supply is 21 million coins, whereas that of Shiba Inu is 1 quadrillion tokens. Some, like Ethereum, do not but rely on some other mechanism to control overall supply.
Analyzing the relationship between a coin's total and max supply can help traders make more informed decisions.