A computer network is a system that connects two or more computing devices, such as computers, mobile phones, servers, and other hardware, to enable the transmission and sharing of data and resources among them

. These devices communicate using common communication protocols over physical (wired) or wireless connections

. The basic components of a computer network include nodes (computing devices or data communication equipment) and links (the transmission media connecting nodes), which can be cables, optical fibers, or wireless signals

. Networks rely on protocols—rules that govern how data is transmitted and received—to ensure proper communication

. Computer networks vary in scale and complexity, from a simple connection between two laptops to the vast global internet, which is a network of networks connecting billions of devices worldwide

. Networks can be classified by their architecture, such as client-server (centralized resource sharing) or peer-to-peer (equal sharing among devices)

. Specialized devices like switches, routers, and access points manage the flow of data within and between networks, ensuring data reaches the correct destination and maintaining security

. Networks enable many modern services, including internet access, email, online commerce, and streaming, making them critical for business, communication, and entertainment

. In summary, a computer network is an interconnected system of devices that communicate and share resources by following defined protocols over physical or wireless connections, facilitating data exchange on scales ranging from local to global