Node
A computer running blockchain software that stores the chain, checks new blocks against the rules, and relays them to peers.
A full node downloads and independently verifies every block and transaction rather than taking another party's word for the result, and it keeps its own copy of the current state. An archive node additionally retains every historical state, which needs far more disk space and is what block explorers and analytics services rely on; a pruned node discards old block data while still validating everything it sees. Nodes gossip transactions and blocks to each other, which is how a broadcast transaction reaches the whole network within seconds. Running a node is how a user verifies rather than trusts, and it is separate from producing blocks.
In practice
A Bitcoin full node rejects a block that pays a larger subsidy than the rules allow, no matter how much hash rate produced that block.
The common misunderstanding
Running a full node earns nothing and is neither mining nor staking; it is verification, and by itself it produces no payment.
The figure this maps to
The number of independent machines observed running the network's software and relaying data.
Limits: Crawlers see only nodes that accept incoming connections, so the many nodes behind home routers, firewalls or private peering are invisible and the count understates the network, while a single operator running several cloud instances is counted several times. Node count does not measure…