Peer-to-peer (often abbreviated as P2P) is a distributed networking or computing architecture that divides tasks or workloads across several computer systems (each one acting as an individual peer). P2P networks can be used to share any kind of digital data, including cryptocurrencies.
Therefore, the structure of a P2P network is sustained by its users, who can both provide and use resources. There is no such thing as a central server or host, which makes P2P systems very different from traditional client-server models, where the data is distributed unidirectionally (from a centralized server to its clients).
The decentralized framework of P2P systems makes them highly resistant to cyber attacks and also more scalable. The more users join it, the more resilient and scalable it gets. Bigger P2P networks achieve high levels of security because there is no single point of failure (inherent to the more traditional models).
The peer-to-peer architecture became popular in 1999 with the release of file-sharing systems, where users could share digital audio files with others without relying on a central server or host. Since then, various P2P networks have emerged. Popular examples with varying use cases include BitTorrent (file-sharing), Tor (anonymous communication software), and Bitcoin (decentralized economic system).