Network infrastructures can vary greatly in terms of:
Size of the area covered
Number of users connected
Number and types of services available
Area of responsibility
The figure illustrates the two most common types of network infrastructures:
Local Area Network (LAN) – A network infrastructure that provides access to users and end devices in a small geographical area, which is typically an enterprise, home, or small business network owned and managed by an individual or IT department.
Wide Area Network (WAN) – A network infrastructure that provides access to other networks over a wide geographical area, which is typically owned and managed by a telecommunications service provider.
Other types of networks include:
Metropolitan Area Network (MAN) – A network infrastructure that spans a physical area larger than a LAN but smaller than a WAN (e.g., a city). MANs are typically operated by a single entity such as a large organization.
Wireless LAN (WLAN) – Similar to a LAN but wirelessly interconnects users and end points in a small geographical area.
Storage Area Network (SAN) – A network infrastructure designed to support file servers and provide data storage, retrieval, and replication.
[Local Area Networks]
LANs are a network infrastructure that spans a small geographical area. Specific features of LANs include:
LANs interconnect end devices in a limited area such as a home, school, office building, or campus.
A LAN is usually administered by a single organization or individual. The administrative control that governs the security and access control policies are enforced on the network level.
LANs provide high speed bandwidth to internal end devices and intermediary devices.
[Wide Area Networks]
WANs are a network infrastructure that spans a wide geographical area. WANs are typically managed by service providers (SP) or Internet Service Providers (ISP).
Specific features of WANs include:
WANs interconnect LANs over wide geographical areas such as between cities, states, provinces, countries, or continents.
WANs are usually administered by multiple service providers.
WANs typically provide slower speed links between LANs.