A node (node, literally a "knot") is a computer connected to a cryptocurrency network and running a special client program. Through it the node exchanges information with other participants: it receives and forwards transactions and blocks, thereby maintaining the viability of the decentralized network. The more independent nodes there are, the more resilient and reliable the network is.
Types of nodes
- Full node — stores the entire blockchain history and independently verifies every transaction and block according to the protocol rules, without trusting other participants.
- Lightweight node — stores only part of the data and partly relies on full nodes for verification, which reduces resource requirements.
The key role of nodes is validation: they check that transactions and blocks comply with the network rules and reject invalid ones. It is precisely the collection of independent nodes that ensures decentralization and prevents any single participant from unilaterally imposing its own rules on the network.
