One-sentence answer

A node runs Bitcoin rules on its own device, independently checks transactions and blocks, and exchanges valid data with peers.

A node performs three basic jobs

It receives data from peers, checks that data against local rules, and relays valid information. A full node also keeps enough block data to independently derive the current state from history.

Running a node is not logging into a company account. It is operating software whose rules you choose.

A node is not a mining machine

Mining hardware performs vast numbers of hashes to compete for blocks; nodes check whether blocks are valid. A person can run a node without mining or operate miners connected to a node.

Verification is much cheaper than producing proof of work, allowing ordinary hardware to supervise the rules.

Going offline does not erase balances

An offline node temporarily stops receiving updates. When it returns, it requests missing blocks from peers and verifies them itself. The network does not depend on one central server remaining online.

Real availability depends on connectivity, bandwidth, software compatibility, and a valid chain—not merely a count of online nodes.

Three things to remember

  1. Nodes receive, verify, and relay data.
  2. Miners produce work; nodes verify the result.
  3. Node count alone does not describe network health.

A common follow-up

Is a phone wallet a full node?

Many phone wallets save storage and bandwidth by using lightweight verification or third-party services. Whether one is a full node depends on its implementation.

Primary sources

Primary sources

These links lead to protocol material, developer documentation, or open-source code—not trading services.

  1. P2P Network — Developer GuideBitcoin.org
  2. Operating Modes — Developer GuideBitcoin.org