Any computer that runs the Bitcoin software and participates in securing the network is called a node. Nodes work as equal peers in the network, and each node is typically connected to at least several other nodes.
A Bitcoin “full node” refers to a computer that runs the Bitcoin software and maintains a complete copy of the network’s transaction record.
Full nodes do not participate in mining. Instead, their work is to validate transactions against their copy of the network’s record. Full nodes also relay transactions to their peers.
Storing a copy of all transactions creates a web of tens of thousands of redundant validators that ensure the network's accuracy and each transaction’s validity. Relaying transactions from one peer to another across the network is called gossipping, which continues until the entire network has received the transaction.
Anyone can download the Bitcoin Core software for free and run a node from their computer.
Miners race to guess an encrypted data puzzle that resets every new block in order to batch and add new transactions to the Bitcoin blockchain.
In the Bitcoin white paper, Satoshi Nakamoto used the term “node” interchangeably for miners and non-mining nodes. The term “node” has come to only refer to non-mining nodes overtime as as specialized ASIC (application-specific integrated circuit) hardware changed mining from its very early years of CPU or GPU mining.
Unlike full nodes, miners enjoy direct financial benefit from their work for the network. Whichever miner successfully solves a new block and adds it to the network claims that block’s reward. Full nodes receive no direct payment for their role.
Mining nodes typically do not keep a full record of all Bitcoin transactions. Instead, miners focus on optimizing connections with other nodes in the network to gather and process transactions as quickly as possible.