Peer-to-peer in the context of Client (computing)

File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include removable media, centralized servers on computer networks, Internet-based hyperlinked documents, and the use of distributed peer-to-peer networking.

File sharing technologies, such as BitTorrent, are integral to modern media piracy, as well as the sharing of scientific data and other free content.

Old media, also called traditional media or legacy media, are the mass media institutions that dominated prior to the internet, particularly print media, film studios, music studios, advertising agencies, radio broadcasting, and television. Old media institutions are centralized and communicate with one-way technologies to a generally anonymous mass audience.

Old media are often contrasted with new media, which are typically computer- or smartphone-based, and are to some extent interactive and comparatively decentralized. These new media enable people to telecommunicate with one another peer-to-peer or through social media platforms, with widespread use and availability through the internet.

Hacktivism (or hactivism; a portmanteau of hack and activism) is the use of computer-based techniques such as hacking as a form of civil disobedience to promote a political agenda or social change. A form of Internet activism with roots in hacker culture and hacker ethics, its ends are often related to free speech, human rights, or freedom of information movements.

Hacktivist activities span many political ideals and issues. Hyphanet, a peer-to-peer platform for censorship-resistant communication, is a prime example of translating political thought and freedom of speech into code. Hacking as a form of activism can be carried out by a singular activist or through a network of activists, such as Anonymous and WikiLeaks, working in collaboration toward common goals without an overarching authority figure. For context, according to a statement by the U.S. Justice Department, Julian Assange, the founder of WikiLeaks, plotted with hackers connected to the "Anonymous" and "LulzSec" groups, who have been linked to multiple cyberattacks worldwide. In 2012, Assange, who was being held in the United Kingdom on a request for extradition from the United States, gave the head of LulzSec a list of targets to hack and informed him that the most significant leaks of compromised material would come from the National Security Agency, the Central Intelligence Agency, or the New York Times.

Technical support, commonly shortened as tech support, is a form of customer service provided to assist users in resolving problems with products such as consumer electronics and software. Technical support is typically delivered through call centers, online chat, and email services. In addition, many companies operate online forums or discussion boards where customers can provide peer-to-peer assistance, a practice shown to reduce the workload and costs of formal support channels.

A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). Since each block contains information about the previous block, they effectively form a chain (compare linked list data structure), with each additional block linking to the ones before it. Consequently, blockchain transactions are resistant to alteration because, once recorded, the data in any given block cannot be changed retroactively without altering all subsequent blocks and obtaining network consensus to accept these changes.

Blockchains are typically managed by a peer-to-peer (P2P) computer network for use as a public distributed ledger, where nodes collectively adhere to a consensus algorithm protocol to add and validate new transaction blocks. Although blockchain records are not unalterable, since blockchain forks are possible, blockchains may be considered secure by design and exemplify a distributed computing system with high Byzantine fault tolerance.

In computer networking, a network service is an application running at the network layer and above, that provides data storage, manipulation, presentation, communication or other capability which is often implemented using a client–server or peer-to-peer architecture based on application layer network protocols.

Each service is usually provided by a server component running on one or more computers (often a dedicated server computer offering multiple services) and accessed via a network by client components running on other devices. However, the client and server components can both be run on the same machine.

Uploading refers to transmitting data from one computer system to another through means of a network. Common methods of uploading include: uploading via web browsers, FTP clients, and terminals (SCP/SFTP). Uploading can be used in the context of (potentially many) clients that send files to a central server. While uploading can also be defined in the context of sending files between distributed clients, such as with a peer-to-peer (P2P) file-sharing protocol like BitTorrent, the term file sharing is more often used in this case. Moving files within a computer system, as opposed to over a network, is called file copying.

Uploading directly contrasts with downloading, where data is received over a network. In the case of users uploading files over the internet, uploading is often slower than downloading as many internet service providers (ISPs) offer asymmetric connections, which offer more network bandwidth for downloading than uploading.

Bitcoin (abbreviation: BTC; sign: ₿) is the first decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown entity published a white paper under the pseudonym of Satoshi Nakamoto. Use of bitcoin as a currency began in 2009, with the release of its open-source implementation. From 2021 to 2025, El Salvador adopted it as legal tender currency before revoking it. As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries.

Bitcoin works through the collaboration of computers, each of which acts as a node in the peer-to-peer bitcoin network. Each node maintains an independent copy of a public distributed ledger of transactions, called a blockchain, without central oversight. Transactions are validated through the use of cryptography, preventing one person from spending another person's bitcoin, as long as the owner of the bitcoin keeps certain sensitive data secret.

In computer networking, upstream refers to the direction in which data can be transferred from the client to the server (uploading). This differs greatly from downstream not only in theory and usage, but also in that upstream speeds are usually at a premium. Whereas downstream speed is important to the average home user for purposes of downloading content, uploads are used mainly for web server applications and similar processes where the sending of data is critical. Upstream speeds are also important to users of peer-to-peer software.

ADSL and cable modems are asymmetric, with the upstream data rate much lower than that of its downstream. Symmetric connections such as Symmetric Digital Subscriber Line (SDSL) and T1, however, offer identical upstream and downstream rates.

Hyphanet (until mid-2023: Freenet) is a peer-to-peer platform for censorship-resistant, anonymous communication. It uses a decentralized distributed data store to keep and deliver information, and has a suite of free software for publishing and communicating on the Web without fear of censorship. Both Freenet and some of its associated tools were originally designed by Ian Clarke, who defined Freenet's goal as providing freedom of speech on the Internet with strong anonymity protection.

The distributed data store of Freenet is used by many third-party programs and plugins to provide microblogging and media sharing, anonymous and decentralised version tracking, blogging, a generic web of trust for decentralized spam resistance, Shoeshop for using Freenet over sneakernet, and many more.

A home network or home area network (HAN) is a type of computer network, specifically a type of local area network (LAN), that facilitates communication among devices within the close vicinity of a home. Devices capable of participating in this network, for example, smart devices such as network printers and handheld mobile computers, often gain enhanced emergent capabilities through their ability to interact. These additional capabilities can be used to increase the quality of life inside the home in a variety of ways, such as automation of repetitive tasks, increased personal productivity, enhanced home security, and easier access to entertainment. Other than a regular LAN that are centralized and use IP technologies, a home network may also make use of direct peer-to-peer methods as well as non-IP protocols such as Bluetooth.

Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on different networked computers.

The components of a distributed system communicate and coordinate their actions by passing messages to one another in order to achieve a common goal. Three challenges of distributed systems are: maintaining concurrency of components, overcoming the lack of a global clock, and managing the independent failure of components. When a component of one system fails, the entire system does not fail. Examples of distributed systems vary from SOA-based systems to microservices to massively multiplayer online games to peer-to-peer applications. Distributed systems cost more than monolithic architectures, primarily due to increased needs for additional hardware, servers, gateways, firewalls, new subnets, proxies, and so on. Distributed systems can also suffer from fallacies of distributed computing. Conversely, a well-designed distributed system is more scalable, more durable, more changeable, and more fine-tuned than a monolithic application deployed on a single machine. According to Marc Brooker: "a system is scalable in the range where marginal cost of additional workload is nearly constant." Serverless technologies fit this definition but the total cost of ownership, and not just the infra cost must be considered.

Briar is an open-source software communication technology, intended to provide secure and resilient peer-to-peer communications with no centralized servers and minimal reliance on external infrastructure. Messages can be transmitted through Bluetooth, Wi-Fi, over the internet via Tor or removable storage, such as USB sticks. All communication is end-to-end encrypted. Relevant content is stored in encrypted form on participating devices. Long-term plans for the project include support for distributed applications such as crisis mapping and collaborative document editing.

The initial target audience for Briar includes "activists, journalists and civil society" with plans to make the system "simple enough to help anyone keep their data safe." As the ability to function in the absence of internet infrastructure may also make the project valuable to disaster response and aid organizations, the developers are working with the Open Humanitarian Initiative and Taarifa. Ultimately, the developers aim to create a system which is "as simple to use as WhatsApp, as secure as PGP, and that keeps working if somebody breaks the Internet." It is possible for an Android device to download Briar from another Android device which already has Briar installed.