In the context of blockchain, what does a node refer to?

In the context of blockchain, a node refers to a computer that participates in the blockchain network. This participation can involve verifying transactions, maintaining a copy of the blockchain, and relaying that information to other nodes in the network. Nodes are essential for achieving the decentralized nature of blockchain technology, as they help ensure the integrity and availability of the data across a distributed system.

These nodes work collectively to validate and record transactions on the blockchain, ensuring that all copies of the ledger reflect the same information. In essence, each node contributes to the network's security and resilience by performing its role independently while still being connected to other nodes.

The other options do not accurately capture the fundamental role of a node in blockchain technology. A user managing their own personal data refers more to an individual's interaction with the blockchain rather than the node itself. An external service accessing the blockchain suggests an interaction without implying participation in the network. A central database storing blockchain records goes against the decentralized principles of blockchain, which is characterized by a distributed network instead of relying on a singular central repository.