A quick link to a practical definition of what an NFT is. First, some context:
After the invention of photography, artists and collectors had to come to terms with the fact that an artist can produce an unlimited number of identical prints of any photograph. The art world’s practical answer to the question of authenticity, and thus collectibility, in the era of mechanical reproduction was signed editions.
And, how an NFT can play a part:
When viewed in this light, the nature of NFTs becomes quite clear. An NFT is a mechanism by which an artist can publicly attach their cryptographic signature to a digital work of art. In other words, it is a technology that supports in the context of digital arts the same kinds of signed editions that have existed in fine art photography for most of a century.