- A Non-Fungible Token (NFT) proves ownership of a digital asset
- Unlike fungible crypto coins, which are identical and worth the same, NFTs are unique.
- An NFT is worth what someone is willing to pay for it, which can be a lot if the NFT is made by a famous artist and the buyer is a wealthy collector.
An NFT is a unit of data stored on a digital ledger, called a blockchain, which can be sold and traded. The NFT can be associated with a particular digital or physical asset (such as a file or a physical object) and a license to use the asset for a specified purpose. NFTs (and the associated license to use, copy or display the underlying asset) can be traded and sold on digital markets.
NFTs function like cryptographic tokens, but, unlike cryptocurrencies like Bitcoin, NFTs are not mutually interchangeable, so not fungible. While all bitcoins are equal, each NFT may represent a different underlying asset and thus have a different value. NFTs are created when blockchains string records of cryptographic hash, a set of characters identifying a set of data, onto previous records therefore creating a chain of identifiable data blocks. This cryptographic transaction process ensures the authentication of each digital file by providing a digital signature that is used to track NFT ownership.
The NFT market value tripled in 2020, reaching more than $250 million. During the first quarter of 2021, NFT sales exceeded $2 billion.
The unique identity and ownership of an NFT is verifiable via the blockchain ledger. Ownership of the NFT is often associated with a license to use the underlying digital asset, but generally does not confer copyright to the buyer: some agreements only grant a license for personal, non-commercial use, while other licenses also allow commercial use of the underlying digital asset.
Non-Fungible Tokens are currently used for digital art, games, collectibles, music, film, memes, sports, fashion, phonography and academia.
ERC-721 was the first standard for representing non-fungible digital assets on the Ethereum blockchain. ERC-721 is an inheritable Solidity smart contract standard, meaning that developers can create new ERC-721-compliant contracts by importing it from the OpenZeppelin library. ERC-721 provides core methods that allow tracking the owner of a unique identifier, as well as a permissioned way for the owner to transfer the asset to others.
ERC-1155 standard offers “semi-fungibility”, as well as providing a superset of ERC-721 functionality (meaning that an ERC-721 asset could be built using ERC-1155). Unlike ERC-721 where a unique ID represents a single asset, the unique ID of an ERC-1155 token represent a class of assets, and there is an additional quantity field to represent the amount of the class that a particular wallet has. The assets under the same class are interchangeable, and the user can transfer any amount of assets to others.