Polkadot Name System (PNS) is a Decentralized Identifier (DID) infrastructure for Polkadot, which uses unique .dot domain names to replace long, meaningless, unreadable, and forgettable addresses. PNS can bind different addresses in a multi-chain ecosystem, bringing together fragmented identities so that users can present themselves more comprehensively. PNS links Web2/Web3 and integrates on-chain and off-chain data, enhancing the interactive experience of gaming, social, DAO, community governance, and more.