Ok, so I just learned something new. I knew Bitcoins were unique but fungible. They can be collected as unique items but not traded because the private key can't be "forgotten". Your proof that you own some value on the blockchain is your ability to sign a transaction with the private key. But if you want to give that value to someone else you have to transact, i.e. sign with your private key. The value is transferred to the recipient's public key or address. You can't transfer the private key because you can't prove you have 't kept a copy.
Here's what I think NFT is. With NFT the token is transfered by a contract on the blockchain. The transaction has a fee in some cryptocurrency and by signing the transaction you are paying the fee and transferring The NFT transfer transaction transfers the NFT from the seller's address to the recipients address. What I have not yet found is an explanation of the payment. Is it part of the transaction or a separate transaction such that when the buyer sees the payment on a different, unrelated address, they complete the transfer of the NFT.
Short version: NFT is yet another digital bubble, a binary beanie baby.