peer-to-peer network

A peer-to-peer network is one where every computer talks directly to other computers as equals, with no central server in the middle. Each machine, called a node or a peer, is both a customer and a server at once — it asks others for information and serves up information in return. This is the opposite of the usual setup, where many users all connect to one company's central computer.

Nodes connect to a handful of neighbors, and information spreads by gossip: when a peer hears something new, like a fresh transaction or block, it passes it along to its neighbors, who pass it to theirs, until the whole network has it — much like word of mouth rippling through a crowd. There is no master copy and no single point that everything flows through, so the network has no obvious bottleneck and no single switch an outsider could flip to shut it down.

This architecture is the foundation that makes a blockchain decentralized and hard to censor. Because the ledger lives on thousands of equal peers spread around the world, there is no headquarters to raid, no central server to seize, and no single owner who can be pressured to alter the records. If some nodes go offline or get blocked, the rest carry on and the network keeps running. Peer-to-peer networking is, quite literally, the plumbing that lets a leaderless system exist at all.