ERC-721 is the original and most widely adopted standard for non-fungible tokens. Each ERC-721 token has a unique identifier, making it a true 1-of-1 asset — no two tokens are interchangeable. The standard was first proposed in 2018 and popularized by projects like CryptoKitties and later by major NFT marketplaces. ERC-721 tokens typically include metadata pointing to an image or media file, a description, and a set of attributes (traits) that define the asset's properties. Common use cases include digital art, profile pictures, domain names, event tickets, and verifiable credentials like certificates and diplomas. All ERC-721 transfers on this network are private by default. ERC-721 Standard→