# PeerStore The PeerStore contains a mapping of peer IDs to PeerData objects. Each PeerData object represents a peer, and each PeerData contains a collection of protocols, addresses, and a mapping of metadata. PeerStore implements both the IPeerStore (peer protocols), IAddrBook (address book), IPeerMetadata (peer metadata) interfaces, which allows the peer store to effectively function as a dictionary for peer ID to protocol, address, and metadata.