Blockchain node is a computer or software instance connected to a blockchain network and performing one or more functions defined by the protocol or implementation.

Depending on its type, a node may store the blockchain history, validate transactions and blocks, relay data to other participants, or maintain only a limited representation of network information.

Common node functions

  • receiving and validating transactions;
  • receiving and validating blocks;
  • relaying network data;
  • storing blockchain state or history;
  • participating in consensus when the protocol requires it.

Common node types include full nodes and light nodes. Their storage, CPU, memory, and networking requirements can differ significantly.