NFTs are also denoted as a unique digital certificate that is constant and never changes. They are the digital reformations of any physical entity. They are unique because they are formed with a set of codes that differs from other NFTs. Hence, one can easily guess their features that include interoperability, uniqueness, non-interchangeable, and non-identical. These NFTs operate on a blockchain that consists of information in each block and node. There are many blockchains like Ethereum, Binance smart chain, Solana, Polygon, etc. https://www.appdupe.com/non-fungible-token-development