NFT stands for non-fungible token. It's similar to creating a token with a supply of just 1 unit that can not be divided into smaller pieces. NFT's can be grouped and have a parent which makes them useful for creating collections. At the moment (may 2021) NFT's are big hype and most of the products offered have no value and are just a way of making a quick buck.
Non fungible tokens are most useful for the creation of contracts.
Giving somebody a NFT can be the equivalent of giving somebody a signed contract.
The autograph on a signed contract gets replaced by a signed message from a public address that is known to be yours and can be proven to be yours by you signing from it.
The contract itself can then be uploaded to a blockchain and the NFT links to this contract and the signed message.
This now allows the contract holder, who bought the NFT, to resell the NFT on the market, and the new owner becomes the new contract owner.
Now you have anonymous contract holders, while on the other side of the contract is a single known individual.
NFT technology opens up many more possibilities especially when plugged in to smart contract. (smartBCH)
Unfortunately it's also open to abuse because of the greed of the average crypto-investor and the lack of crypto education.