I had to look it up:

What’s an NFT?

NFTs allow you to buy and sell ownership of unique digital items and keep track of who owns them using the blockchain. NFT stands for “non-fungible token,” and it can technically contain anything digital, including drawings, animated GIFs, songs, or items in video games. An NFT can either be one-of-a-kind, like a real-life painting, or one copy of many, like trading cards, but the blockchain keeps track of who has ownership of the file.