Difference Between LAN & WAN Wireless Routers

By David Weedmark

Routers sit between the LAN and WAN.
i Thomas Northcut/Photodisc/Getty Images

To understand the role of a wireless router, it's important to know the difference between a local area network and a wide area network. Simply stated, when you connect to a wireless router with a computer or smartphone, it becomes part of the LAN. Everything outside of this LAN -- basically the entire Internet -- is the WAN.

Understanding LANs

As its name implies, a LAN is a network limited to a small area, like a home or office, and is usually confined to a single building. The LAN can consist of computers, smartphones, TVs and tablets. A wireless LAN is usually limited to the radius of a wireless access point which can be a couple of hundred feet. However, this distance can be extended by linking additional wireless access points to the network. A Wi-Fi router is an example of a wireless access point.

Understanding WANs

A WAN is a network covering any large geographic area. WANs can be as large as a state, a country, or the world. The Internet itself is a type of WAN, because it covers the entire globe. Although a network connecting LANs in the same city, like a group of offices belonging to the same company, these are usually called metropolitan area networks.

Router LAN and WAN Ports

Most wireless routers have at least two ports: one WAN port and one or more LAN ports. In all homes and most small businesses, the WAN port connects to a high-speed modem, like a DSL or cable modem, which in turn connects the router to the Internet. This port is labeled either "WAN" or "Internet," depending on the manufacturer. The LAN ports are used to connect computers that don't have Wi-Fi access using an Ethernet cable. Once connected, these computers can access the Internet and other computers on the LAN, just like those that use Wi-Fi.

The Router's Role

A wireless router has two main roles: Internet sharing and protection. In order to receive data from the Internet, like email or Web pages, every computer connected to the Internet needs an Internet Protocol address, which is supplied by your Internet service provider. Without an IP address, other computers don't know where to send requested data. The router acts as a gatekeeper between the LAN and the Internet. It uses the Internet IP address itself and then provides computers on the LAN with their own IP addresses, which can't be seen outside of the LAN. Because computers outside of the LAN don't know the IP addresses supplied by the router, they can't access those computers without permission, making it difficult for hackers or malevolent software to get to computers on the LAN. Other router features like encryption add even more security to the LAN.