A client node refers to a program running on a computer that interacts with a blockchain network. It plays a crucial role in maintaining the network by validating transactions and blocks, ensuring compliance with the protocol rules.These nodes can either be full nodes or light nodes. Full nodes download and store the entire blockchain, providing maximum security and contributing to the network’s decentralization. They validate all transactions independently, making them essential for the integrity of the system.Light nodes, on the other hand, only download a portion of the blockchain. They depend on full nodes for information and are less resource-intensive, making them suitable for devices with limited capacities, like smartphones.Client nodes are fundamental for participating in the network. They allow users to send and receive transactions, access balances, and interact with various applications built on the blockchain. Their ability to communicate with one another helps maintain the network’s consensus and overall functionality.