A non-fungible token is a unique and non-interchangeable unit of data stored on a blockchain, a form of digital ledger.
NFTs can be associated with reproducible digital files such as photos, videos, and audio.

For example: Essentially, NFTs are like physical collector’s items, only digital. So instead of getting an actual oil painting to hang on the wall, the buyer gets a digital file instead. You also get exclusive ownership rights. NFTs can have only one owner at a time. NFTs’ unique data makes it easy to verify their ownership and transfer tokens between owners. The owner or creator can also store specific information inside them. For instance,
artists can sign their artwork by including their signature in an NFT’s metadata.

What Are NFTs Used For?
Blockchain technology and NFTs afford artists and content creators a unique opportunity to monetize their wares.
For example, artists no longer have to rely on galleries or auction houses to sell their art. Instead, the
artist can sell it directly to the consumer as an NFT, which also lets them keep more of the profits.

Source: Forbes