Fungible

Fungibility is a good or asset’s interchangeability with other individual goods or assets of the same type.

Fungible Token

Fungible tokens issued on a blockchain can be exchanged for another token that is of the same type (on Ethereum, these tokens are following the ERC-20 token standard).

Non-Fungible Token

Tokens that are, by definition, non fungible. Meaning that they represent a unique digital item, and are not inter exchangeable. But like any other unique item, they can be priced in any other (fungible) currency (on Ethereum, these tokens mostly follow the ERC-721 token standard).