network

A network is a system of interconnected devices that share resources and exchange information. In computing, networks link computers, servers, printers, and other equipment to enable data transfer, collaborative work, and access to services such as the Internet. Networks can be wired, using physical media like copper or fiber, or wireless, employing radio waves and other air methods. They may span a single room or extend across continents.

Networks appear in several domains. Social networks connect people through relationships and interactions. Biological networks describe systems such as metabolic and gene-regulatory networks. Neural networks, a class of algorithms modeled on brain structure, process information and make decisions.

A network comprises nodes and links. Nodes are devices that originate, route, or receive data; links are the communication channels. Routers, switches, modems, and endpoints perform specialized roles. Topology describes how nodes are arranged: common forms include star, bus, ring, and mesh. Networks are categorized by geographic scope as local area networks (LANs), metropolitan area networks (MANs), wide area networks (WANs), and personal area networks (PANs). Data flows are governed by protocols, such as Ethernet for local links and the Internet Protocol Suite (TCP/IP) for end-to-end communication. The OSI model and the TCP/IP model describe layered approaches to network functions, from physical transmission to application services.

Key performance characteristics include bandwidth, latency, throughput, reliability, and scalability. Network management covers addressing, routing, quality of service, and security. Security considerations include encryption, authentication, access control, and monitoring for threats such as eavesdropping, tampering, and denial-of-service. Networks have profoundly shaped information exchange, commerce, and collaboration, and continue to evolve with wireless technologies, cloud computing, and software-defined networking.