Peer to peer is an approach to computer networking where all computers share equivalent responsibility for processing data. Peer-to-peer networking (also known simply as peer networking) differs from the previously described, client-server networking, wherein some devices have the responsibility of providing or 'serving' data and other devices consume or otherwise act as 'clients' of those servers.
Peer to peer networking is common on small local area networks (LANs), particularly home networks. Both wired and wireless home networks can be configured as peer to peer environments.
Computers in a peer to peer network run the same networking protocols and also similar software. Peer networks are often positioned physically near each other, normally in homes, schools or small businesses. Some of the peer networks can also use the Internet and are geographically dispersed worldwide.
Home networks that utilize broadband routers are hybrid peer to peer and client-server environments. The job of the router is to provide a centralized Internet connection sharing, but the sharing of printer, file and other resources is managed directly between the local computers involved.
Internet-based peer to peer networks emerged in the 1990s due to the development of P2P file sharing networks like Napster. Technically, many P2P networks (including the original Napster) are not pure peer networks but rather hybrid designs as they utilize central servers for some functions such as search.
Wi-Fi wireless networks support so-called ad hoc connections between devices. Ad hoc Wi-Fi networks are solely peer to peer compared to those implementing wireless routers as an intermediary device.
You can configure computers in peer to peer workgroups to allow sharing of printers, files and various other assets across all of the devices. A main advantage of peer networks is that they simplify the process of data sharing in both the directions, either for downloads to your computer as well as for uploads from your computer.
On the Internet, peer to peer networks handle a very high volume of file sharing traffic by distributing the load across many computers. As they do not depend exclusively on centralized servers, P2P networks both levels higher and are far more resilient than client-server networks in case of failures or traffic bottlenecks.