A graph node refers to a point in a network that represents a single element or entity. In the context of blockchain systems, each node can hold data about transactions, smart contracts, or account balances.Nodes work together to verify and record transactions, ensuring data integrity across the network. These nodes can be categorized as full nodes, which maintain a complete copy of the blockchain, or light nodes, which hold only essential information and rely on full nodes for verification.Nodes communicate with each other to maintain the distributed ledger. They also play a critical role in consensus mechanisms, helping to validate new transactions and adding them to the blockchain. The performance and reliability of a blockchain can depend significantly on the number and quality of its nodes.In summary, nodes are vital components that enable the functioning of blockchain systems, assisting in data storage, transaction verification, and maintaining the overall security of the network.