Non-fungible tokens (NFTs) are cryptographic assets on a blockchain with unique identification codes and metadata that distinguish them from each other.
Unlike cryptocurrencies, they cannot be traded or exchanged at equivalency. This differs from fungible tokens like cryptocurrencies, which are identical to each other and, therefore, can serve as a medium for commercial transactions.
Like physical money, cryptocurrencies are fungible, meaning that they can be traded or exchanged, one for another. For example, one bitcoin is always equal in value to another bitcoin. Similarly, a single unit of ether is always equal to another unit. This fungibility characteristic makes cryptocurrencies suitable as a secure medium of transaction in the digital economy.
NFTs shift the crypto paradigm by making each token unique and irreplaceable, thereby 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 “breed” a third, unique NFT.
ERC-721 defines the minimum interface—ownership details, security, and metadata—required for the exchange and distribution of gaming tokens.