A network consists of two or more separate devices (laptops, printers, servers, etc.) that are linked together so they can communicate. Each device on a network is called a node, and various nodes can be connected physically through cables or wirelessly through radio frequencies.
Networks are useful for a variety of reasons, chief among them being information sharing. Nodes on a network often share software, storage, data, and access to input or output devices. Not only does this make resource allocation more economical, but it also makes each device more efficient.
Types of computer networks
Most types of networks are characterized by their physical location (or lack thereof):
- Local-area networks (LANs) have computers that are close in proximity to each other, usually in the same building.
- Wireless local-area networks (WLANs) are, as the name suggests, LANs that are connected through high frequency radio waves as opposed to cables.
- Wide-area networks (WANs) consist of two or more interconnected LANs and are not tied to any physical location.
- Campus-area networks (CANs) are also composed of two or more LANs, but they are bound by a physical perimeter.
- Metropolitan-area networks (MANs) are data networks designed for a town or city.
- Home-area networks (HANs) are contained within a user’s home and connect all devices together, from computers to security systems to smart home devices and more.
- Storage-area networks (SANs) are composed of storage devices on a high-speed server.
- Virtual private networks (VPNs) are Internet-based and use tunneling protocols to establish a secure connection between a client and server.
Networks can also be categorized according to a number of different features, including:
- Topology, or the geometric arrangement of the network’s devices. Common topologies include bus, star, ring, and tree. Diagrams of different topology configurations can be found in the Quick Reference section of Webopedia.
- Protocol, or the set of rules and signals that the computers on a network use to communicate. Common network protocols include Hyper Text Transfer Protocol (HTTP), Internet Protocol (IP), Transmission Control Protocol (TCP), and Simple Mail Transport Protocol (SMTP).
- Architecture, or the structure of task distribution among connected devices. The primary types of network architecture are peer-to-peer (P2P), which is used primarily for file sharing, and client/server, which is used primarily for resource management. It’s worth noting that most devices P2P architectures share equal weight, whereas client/server architectures have a distinct hierarchy, with most of the power centralized in the server.