Networks

Networks are systems of interconnected elements that communicate and share resources. They enable data, power, or people to connect. They consist of nodes (devices, users, servers) and links (cables, wireless channels) and rely on standards and protocols to manage addressing, transmission, and error handling. Design choices affect performance and reliability.

Types include computer networks, which connect devices for data exchange and resource sharing (LANs, WANs, MANs). Social networks map relationships among people or organizations. Biological networks model interactions among molecules, genes, or cells, while artificial neural networks are computational models inspired by the brain. Infrastructure networks such as electrical grids or water systems also fall under the general concept of networks.

Architecture and components: nodes perform sending or consuming data; links carry signals; routers, switches, and gateways manage flows. Protocols define rules for communication, including addressing, error checking, and flow control. Topologies describe node arrangements (star, bus, ring, mesh); layered models such as OSI or TCP/IP organize functions.

Function and performance: networks enable communication, remote access, and resource sharing; services such as email, web, and file transfer rely on them. Key metrics include bandwidth, latency, jitter, packet loss, and reliability. Security concerns include unauthorized access, interception, and tampering, mitigated by authentication, encryption, and access controls.

The Internet is a global network of networks built on standardized protocols, primarily TCP/IP, enabling interconnection across borders. The concept evolved from telegraph and telephone networks to packet switching, leading to ARPANET and the modern Internet.