Bitcoin and Crypto Talk (Merged)(includes NFT)

NFT = Non Fungible Token

Not sure there is a simple explanation. The best I can do is an NFT Is a digital asset that in principal, cannot be duplicated on the blockchain on which it resides - hence the "non-fungible" part. Cryptocurrency tokens, such as Bitcoin, Dogecoin, Shiba, etc. are all fungible tokens - meaning one is indistinguishable from another, and there is no inherent maximum* . NFTs require a "smart-contract" based blockchain, such as Ethereum. The Bitcoin blockchain can't do it (by itself - although it could be involved in the sale in an indirect way - this is a complicated issue). The "cannot be duplicated" part also has some fine print/provisos, it has a meaning in a technical sense which may not correspond to peoples expectations.

Besides the autographs and artwork, etc. A potentially real-world useful application is ticketing. It would require the issuer to sell the tickets as an NFT. Depending on how the issuer smart contract works, they could allow the buyers to resell the tickets on an open market, without involving the original issuer, and with both buyers and sellers protected from fraud - as a buyer you could be certain the ticket was authentic, with minimal dillegence, as a seller you could be certain you received payment, and depending on the blockchain, with very low transaction fees. Practically, maybe this never happens as the benefit to the issuer is questionable, its more a benefit to the consumer, although market forces might change this. And on the other hand, the issuer could use a smart contract which actually prevents resale - e.g., how airline tickets work. Either way, the "efficiency" of the transactions should increase as the authentication end is handled by the blockchain.

* Yes, wrt to Bitcoin there is a hard limit of ~21 million Bitcoins But this could be raised by majority agreement of the network.