Visual Index of Computer Networking

This guide to networks breaks down the topic into a series of visual exhibits. Each section features one key concept or element of wireless and computer networking.

This diagram illustrates the simplest possible kind of computer network. In a simple network, two computers (or other networkable devices) make a direct connection with each and communicate across a wire or cable. Simple networks like this have existed for decades. A common use for these networks is file sharing.

A Local Area Network (LAN) With Printer

WAN Blueprint

This diagram illustrates a typical local area network (LAN) environment. Local area networks often feature a group of computers located in a home, school, or part of an office building. Like a simple network, computers on a LAN share files and printers. Computers on one LAN can also share connections with other LANs and with the Internet.

Wide Area Networks

Internet Backbone

This diagram illustrates a hypothetical wide area network (WAN) configuration that joins LANs in three metropolitan locations. Wide area networks cover a large geographic area like a city, a country or multiple countries. WANs normally connect multiple LANs and other smaller-scale area networks. WANs are built by large telecommunication companies and other corporations using highly-specialized equipment not found in consumer stores. The Internet is an example of a WAN that joins local and metropolitan area networks across most of the world.

Wired Computer Networks

Local Area Network

This diagram illustrates several common forms of wiring in computer networks. In many homes, twisted-pair Ethernet cables are often used to connect computers. Phone or cable TV lines, in turn, connect the home LAN to the Internet Service Provider (ISP). ISPs, larger schools, and businesses often stack their computer equipment in racks (as shown), and they use a mix of different kinds of cable to join this equipment to LANs and to the Internet. Much of the Internet uses high-speed fiber optic cable to send traffic long distances underground, but‚Äča twisted pair and coaxial cable can also be used for leased lines and in more remote areas.

The OSI Model of Computer Networks

Network Model

This diagram illustrates the Open Systems Interconnection (OSI) model. OSI is primarily used today as a teaching tool. It conceptually devises a network into seven layers in a logical progression. The lower layers deal with electrical signals, chunks of binary data, and routing of these data across networks. Higher levels cover network requests and responses, representation of data, and network protocols as seen from a user’s point of view. The OSI model was originally conceived as a standard architecture for building network systems and indeed, many popular network technologies today reflect the layered design of OSI.