Like physical money, cryptocurrencies are usually fungible from a financial perspective, meaning that they can be traded or exchanged, one for another. For example, one bitcoin is always equal in value to another bitcoin on a given exchange, similar to how every dollar bill of U.S. currency has an implicit exchange value of $1. This fungibility characteristic makes cryptocurrencies suitable as a secure medium of transaction in the digital economy. 5
For this reason, NFTs shift the crypto paradigm by making each token unique and irreplaceable, making it impossible for one non-fungible token to be "equal" to another. They are digital representations of assets and have been likened to digital passports because each token contains a unique, non-transferable identity to distinguish it from other tokens. They are also extensible, meaning you can combine one NFT with another to create a third, unique NFT.