In cryptocurrency, the term fungible refers to a coin or token that can be easily replaced by another identical coin or token. Fungibility allows a token’s ability to maintain a particular standard value.
This way, the currency’s history cannot affect its value. So any two given coin or token has the same value, making them mutually interchangeable. But at the same time, when any fungible token is given an identifying mark or serial number, it becomes non-fungible.