What Is a Router for Computer Networks?

Routers make it possible for devices to communicate between networks

A TP-Link router with a full range of network lights on.

Firecracker PR / CC BY 2.0 / Flickr

Routers are small electronic devices that join multiple computer networks together using either wired or wireless connections.

How Routers Work

In technical terms, a router is a Layer 3 network gateway device, meaning that it connects two or more networks and that the router operates at the network layer of the OSI model.

Routers contain a processor (CPU), several kinds of digital memory, and input-output (I/O) interfaces. They function as special-purpose computers, one that does not require a keyboard or display.

The router memory stores an embedded operating system (OS). Compared to general-purpose OS products such as Microsoft Windows or Apple macOS, router operating systems limit what kind of applications will run on them and also need smaller amounts of storage space. Examples of popular router operating systems include Cisco Internetwork Operating System (IOS) and DD-WRT. These operating systems are manufactured into a binary firmware image and are commonly called router firmware.

By maintaining configuration information in a part of memory called the routing table, routers filter incoming and outgoing traffic based on the addresses of senders and receivers.

Routers for Business Networks and the Internet

Before home networking became popular, routers were found in businesses and schools. These routers cost thousands of dollars and require special technical training to set up and manage.

The largest and most powerful network routers form the internet backbone. These routers manage many terabits of data flowing through and between internet service provider (ISP) networks 

Home Broadband Routers

Routers became mainstream consumer devices when households began to accumulate multiple computers and wanted to share a home internet connection

Home networks use Internet Protocol (IP) routers to connect computers to each other and to the internet. Early generations of home routers supported wired networking with Ethernet cables while newer wireless routers supported Wi-Fi together with Ethernet. The term broadband router applies to any home wired or wireless router used to share a broadband internet connection.

Home routers often cost $100 or less. They are manufactured to be more affordable than business routers in part because they offer fewer features. Still, home routers provide many essential home networking functions:

  • Share a home internet connection with dozens of devices.
  • Provide basic home network firewall and other security support.
  • Change router configuration settings from a web browser.

See our updated Best Wireless Routers to Buy guide for help choosing the router that's best for you.

Other Types of Routers and Routing Devices

A class of portable Wi-Fi routers called travel routers are marketed to people and families who want the functions of a personal router when they're traveling and away from home.

Routing devices called mobile hotspots that share a mobile (cellular) internet connection with Wi-Fi clients are also available. Many mobile hotspot devices work with certain brands of cellular service.

Choosing a Router

There are many types of routers. From least expensive to top-rated, below are some of the routers available:

802.11ac Routers

  • Linksys EA6500: This is the first Linksys smart WiFi router and gives users total mobile control of the wireless network in their home.
  • Netgear AC1750 (R6300): A solid choice for big homes with a lot of wireless devices.

802.11n Routers

  • Netgear N300 WNR2000: This is a quality router and the limited lifetime warranty means if you run into any issues while using it, you can contact Netgear to fix the problem.
  • TP-LINK TL-WR841N: TP-LINK routers are some of the most sought after ones on the market. The TL-WR841N features external antennas that make a stronger connection.

802.11g Routers

  • Netgear WGR614: The WGR614 is a first-rate router with a wide signal range that's ideal for homes with brick walls or similar obstructions. And, a three-year warranty is included.
  • Linksys WRT54G Wireless-G: This Linksys router doesn't take any time to install and its strong signal range means no more slow-loading pages.