I've tried to break down the definition of an NFT
Using simple words and concepts.
To understand NFT, let's first take on fungible tokens.
What Fungible means. ( Eg BTC)
A Fungible asset = can be easily interchanged without change to the asset.
E.g. Gold, 1g of gold = 1g of gold,
If you swap your gold with another person for the same weight, you will not suffer any loss in the asset exchanged.
You can switch them, and they will still be worth the same thing.
Gold, Money & Bitcoin are fungible.
1Btc is still 1Btc no matter what.
A token is a digital asset that is stored on the blockchain
Digital assets are entries into a blockchain, i.e. a distributed ledger technology. (DLT)
They can be Fungible or Non-fungible depending on the token standard. ( Eg in the case of etheurem Erc-20 or Erc-721 )
Non-fungible means simply;
they cannot be exchanged 1 for 1 like for like.
You would be exchanging two different things,
they may share similarities, but one cannot say they are fungible.
The idea of this standard and the technical functionality that delivers this status are nuanced.
A Cristiano Ronaldo match attack card is an NFT;
it cannot be exchanged with another card and say it was like for like.
It may be a different condition, and it may be a different coloured print, a different number in the sequence.
They are non-fungible when it comes to exchanging.
NFTs. are non-fungible tokens on a DLT such as the Ethereum blockchain (ETH).
They are created underneath smart contracts, which live on the ethereum virtual machine.
NFTs are entries into the ledger created underneath smart contracts; they mint an Erc-721 token from the smart contract to create an NFT.
They are an NFT minted under a custom smart contract.
The code is to create a collection of a finite number of tokens that can be minted from the smart contract.
Each token is a unique instance of code on the blockchain.
NFTs can be linked to any type of digital file; any multimedia file can be in a few different ways intrinsically or extrinsically linked to an NFT linked to a smart contract and the wallet that deployed it.
In the example, a JPEG file is linked to each token in the cryptopunk smart contract, also called a collection.