Non-fungible token (NFT): A non-fungible token (NFT) is a special token on a blockchain that can be used to prove ownership of an asset. NFTs can be thought of as a digital representation of an asset. Unlike other tokens, a non-fungible token cannot be used freely as a means of payment, but serves solely as proof of ownership (e.g. of a work of art or a patent). Artists sell / auction their works via NFT platforms, for example. The previous auction record for digital art was set by the American Beeple in mid-March 2021: a digital collage of 5,000 small Beeple images was worth the equivalent of around USD 58 million to a collector. (Publication date 15/03/2021)
See https://www.blockchain-insider.de/was-ist-nft-a-1019258/ resp.