In a blockchain network, nodes refer to the physical devices or electronic devices, such as computers, servers, or printers, that maintain copies of the blockchain's data, webbing the network together and keeping it operational. Their primary function is to maintain consensus on the blockchain's public ledger, which varies from one type of node to the next. Nodes are moderators that build the infrastructure of a decentralized network, and they ensure that all users play by the rules, providing security and transparency to the network. Nodes are responsible for syncing and updating all copies of the ledger, storing encrypted data of past transactions, and executing transactions based on a majority consensus. In short, nodes accept or reject proposals and ensure that all nodes remain in sync, reflecting the true state of the blockchain.