A non-fungible token (NFT) is a unit of data on a digital ledger called a blockchain, where each NFT can represent a unique digital item, and thus they are not interchangeable. NFTs can represent digital files such as art, audio, video, and other forms of creative work. While the digital files themselves are infinitely reproducible, the NFTs representing them are tracked on their underlying blockchains and provide buyers with proof of ownership. The common blockchains such as Ethereum, Bitcoin Cash, Flow, etc. each have their own token standards to define their use of NFTs.