A node refers to a computer that connects to a blockchain network and communicates with other participants to ensure the security and integrity of the system.
Each blockchain node serves as a network communication point. There are various types of nodes, each of which is accountable for a different set of tasks. Take Bitcoin as an example: full nodes, listening nodes (supernodes), miner’s nodes, and lightweight or SPV clients are the four basic kinds of network nodes.
Full nodes are the only ones who can truly support and safeguard the Bitcoin blockchain, and they are critical to the network’s success. The entire nodes that are made publicly visible and accessible are referred to as listening nodes, or supernodes. As such, they can communicate with any other node that establishes a connection with them.
Meanwhile, the mining nodes, as well as ASIC machines, are the ones that run specialized mining software (in most cases). Lastly, the lightweight or SPV clients are the ones that use the Bitcoin blockchain but don’t function as validating nodes. They collect data from supernodes and serve as a communication endpoint.