A node network refers to a collection of computers, called nodes, that participate in maintaining and operating a blockchain. Each node stores a copy of the entire blockchain, ensuring that the data is decentralized and not dependent on a single server.Nodes communicate with each other to validate and confirm transactions. When a user initiates a transaction, it gets broadcast to the network, allowing nodes to verify it through consensus mechanisms. This process helps prevent issues like double spending and fraud.Nodes can operate in different capacities. Some fulfill lightweight roles by storing minimal data, while others serve as full nodes that maintain the entire blockchain history. There are also miner nodes that validate transactions and create new blocks in proof-of-work systems, earning rewards in the process.Overall, the node network is crucial for the security, transparency, and reliability of a blockchain, making it resilient against attacks and failures. The more nodes there are, the stronger the network becomes, fostering trust among users and participants.