Fungible
Can replace or be replaced by an identicle item, they are mutually interchangeable. i.e. A United States Dollar is fungible.
Non-Fungible
Can not be replaced and can only have identicals in declared editions. i.e. A piece of art, a limited edition baseball card, both are non-fungible.
Fungible Tokens
Can digitally replace or be replaced by an identicle digital item, they are mutually interchangeable. i.e. Bitcoin & Ethereum ERC 20 Tokens are fungible.
Non-Fungible Tokens (NFTs)
Can not be digitally replaced and can only have identicals in declared editions. i.e. A NBA Top Shot, A PiXXXL, both non-fungible tokens (NFTs).