Peer-to-peer

A computer network is considered peer-to-peer (P2P) if the independent computers (i.e. the "peers") are connected to each other directly via the internet without an intermediary to facilitate the connection. P2P networks are decentralized such that no single node/peer controls the system. This means that each computer (aka node) in a P2P network may act as both a server and a client, and computer resources such as files and data can be transferred between the participating computers directly.

An economy is considered peer-to-peer if it has a decentralized model in which two individuals can exchange goods and services directly with each other, without a third-party to facilitate the exchange.

• Gnutella - The first decentralized P2P file sharing network (developed in 2000), available on Windows, Linux, and Mac.
• Napster - P2P file sharing service launched in 1999 by a 18-year-old student at Northeastern University, shut down after a heated legal battle and converted into a legal music subscription service in 2001.
• BitTorrent - Free P2P client with an open-source protocol, commonly used to download applications, software, movies, music, etc.
• LimeWire - P2P file sharing application launched by former Wall Street trader Mark Gorton in 2000 and forced to shut down in 2010.
• eBay - Online P2P marketplace where goods are auctioned off to the highest bidder.
• Silk Road - Online P2P marketplace founded in 2011 by Ross Ulbricht that facilitated many black market transactions involving drugs, guns, and document forgeries, among other things.
• Bitcoin - First ever decentralized P2P digital currency built using blockchain technology, invented by Satoshi Nakamoto in 2008.