In blockchain, a 'node' is any computer that is connected to the network and supports its operation. Nodes ensure the reliability, decentralization, and resilience of the blockchain.
Types of nodes:
Full nodes: store a complete copy of the blockchain, verify each transaction and block. They are the foundation of network reliability.
Light nodes: do not store the entire history but load only the necessary information. They are used in wallets and applications.
Mining/validator nodes: participate in the creation of new blocks, depending on the algorithm (PoW or PoS).
Functions of nodes:
-Verification of transactions and blocks
-Data distribution across the network
-Storage of blockchain history
-Participation in consensus (if it is a validator/miner)
Why is this important?
The more independent nodes in the network, the more decentralized and resilient the blockchain is. Nodes make 'centralized control' impossible and ensure transparency of all processes.