Peer to peer software is computer software which enables people to make peer to peer connections, either over the Internet or over a network in a location such as a home, office, or university. Peer to peer communications allow people to communicate with each other directly, with each computer in the network acting as both a client and a server. These systems can be designed to be permanent or transient in nature, depending on the needs of the users and the system.
The highly decentralized communications allowed by peer to peer software can be very useful for a range of situations. Such communications networks are less likely to experience catastrophic failure, because users aren't relying on a limited number of servers. They can also be designed to promote confidentiality for users, which can be a concern when sensitive information is exchanged, and they limit the risk of exposure to legal liabilities, which is why they have become so popular for illegal file sharing.
When illegal materials are stored on the server, the host of the server is liable. With peer to peer software, however, people can exchange files directly with each other, with the software acting only as a facilitator for the exchange. Therefore, legal liabilities lie with the file sharers alone, as they act as the hosts for the illegal material. In the wake of growing concerns about the piracy of software, films, and music, many people who engage in such activity have switched to using peer to peer software for their downloading and uploading for this reason.
There are, of course, many legitimate reasons for people to use peer to peer software. Such software can enable the legal exchange of a wide variety of file types, ranging from documents being distributed among editors to audio files sent by musicians working on new tracks. This software can also be used for Internet telephony, allowing two users to video or audio conference with each other. People living in remote locations may find it cheaper to communicate with distant friends regularly with peer to peer software, in contrast with picking up a phone.
P2P, as it is known, is available for free from many producers, and it can also be purchased. When downloading P2P software, people should be very careful, as the software can come with malware attached, and users may expose themselves to computer viruses by using peer to peer software, because the system has no safety nets. It's important to accompany the use of such software with aggressive antivirus software, and to report suspected viruses to network administrators properly. Even if the virus was contracted in the course of doing something illegal, a network administrator is far more interested in protecting other computers on the network than in the actions of a single user.