The original categories of area networks (networking) are LAN and WAN.
LAN – Local Area Networks – is used to refer to networks that are limited to a particular/single site, building or location; connecting network devices over a relatively short distance (e.g. office building, school, or home etc…). LANs are used when an organization remains within a single location, however when the organization expands beyond their own premises/location, a WAN is needed to geographically network the separate areas of the organization together. Sometimes one building will contain a few small LANs (e.g. one per room), with a LAN occasionally spanning a group of nearby buildings.
The network topology of LAN is peer-to-peer networking, where the resources are shared between terminals. In general, LAN networks are cheaper as they do no rely on leased lines and utilize less hardware.
In addition to operating in a limited space, LANs are also typically owned, controlled, and managed by a single person/organization. They tend to use certain connectivity technologies such as Ethernet and Token Ring (primarily).
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WAN – Wide area Networks- is used to refer to networks that are not limited to a particular/single site, building or location. WANs are a dispersed collection of LANs: they make it possible for businesses to communicate across great distances as they connect user networks over a large geographical area. (CCNA 1 & 2 2003)
The network topology of WAN is more client based (rather than server based), with central servers and ISPs (Internet Service Providers), and spans a larger physical distance than LAN. For example, the internet is the largest WAN which spans the Earth.
A router (networking device) connects LANs to WANs, and in IP networking, the router maintains both a LAN and WAN address respectively. Unlike LANs which are typically owned, controlled, and managed by a single person/organization, WANs (e.g internet) are not owned by any specific organization, but rather its (the internet) existence is under a collective/distributed ownership and management. The technologies that WANs use for connectivity over longer distances are ATM, Frame Relay, and X.25.
- CCNA 1 and 2. (2003). “Companion Guide, Networking Fundamentals”. 3rd ed. Cisco press: Indianapolis, USA.