What is a node in a blockchain network?

In a blockchain network, a node refers to a computer or device that connects to the network and helps maintain the integrity of the blockchain by verifying and validating transactions. Each node in the network stores a copy of the entire blockchain ledger and can participate in the consensus mechanism to ensure that new blocks are added to the chain only when they are valid. Nodes can be classified as either full nodes or light nodes, with full nodes having a complete copy of the blockchain ledger and light nodes relying on other nodes for verification.