ERC-721 is a type of smart contract that was introduced in the Ethereum blockchain to allow the creation of unique, non-fungible tokens. Unlike the traditional ERC-20 tokens, which are fungible and represent a specific unit of value, ERC-721 tokens are unique and cannot be replaced or exchanged with other tokens. This makes them suitable for applications like digital collectibles, virtual real estate, and gaming items.
Each ERC-721 token has its own unique identifier, so no two tokens are exactly the same. This allows for the creation of one-of-a-kind digital assets that can be bought, sold, and traded. Additionally, because ERC-721 tokens exist on the Ethereum blockchain, they are stored on a decentralized ledger and can be accessed from anywhere in the world.
The ERC-721 standard has been widely adopted in the cryptocurrency world and has been used to create several popular decentralized applications, such as CryptoKitties, a game that allows players to breed, trade, and sell digital cats. ERC-721 tokens are often seen as a way to bring the idea of ownership to the digital world, making it possible to own unique assets in the same way that we own physical assets.