Routers versus Modems in Wireless and Computer Networking

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Home computer networks feature both modems and routers as core components. Both are specialized pieces of electronic hardware that work together, sometimes made by the same companies and sometimes even integrated together into one physical device. Yet modems and routers serve two different purposes.

Homeowners should learn as much as possible about modems and routers to master home network setup and management.

What is a Modem?

A modem technically converts electronic signals from one network for use on another network. Modems connect home networks to the Internet.

Traditional dialup network modems converted signals from PCs and other digital devices into the analog signals that telephone lines support. Broadband modems convert digital signals of the home network into the other digital forms needed for various kinds of broadband Internet service.

See our Best Cable Modems to Buy guide for help choosing one.

What is a Router? 

A network router links devices together into one or more local networks and then interfaces those networks to outside ones.

Home broadband routers are a category of routers designed to connect a variety of consumer devices to each other and to a shared broadband Internet connection.

Our Best Wireless Routers to Buy guide can help with this decision.

Modems vs. Routers for Home Networking

Aside from the power cable, a typical consumer modem has only two physical network connection points (called ports):

  • one for the Internet line. A modem’s Internet ports can be RJ-45 jacks (for DSL Internet), coax (for cable Internet), and so on.  Modems may label these ports as “WAN,” “Internet” and “line.”
  • one for the home network. A modem’s home network facing port can be either Ethernet or USB and is often marked as “LAN.”

    Home routers usually feature at least five ports in addition to power:

    • one for a modem, called “WAN,” “Internet” or “uplink.”
    • four or five (but sometimes only one) for Ethernet cables that link to local devices such as computers, printers and game consoles
    • plus optional USB ports for portable storage or printers

    Also unlike modems, wireless home routers feature built-in radios (with either internal or external antennas) to support Wi-Fi clients.

    The Use of Routers and Modems in Home Networks

    When both devices are present, the modem plugs into the router and sits between it and the Internet line.

    Home networks require a modem to access the Internet. However, a home network without Internet access can still be useful as it enables file, printer and storage sharing among the local clients.

    Home networks technically do not require a router. A single device such as a laptop can plug into the Internet modem directly.  With non-trivial effort, a PC or laptop can be configured to support a wireless LAN (WLAN) and share the modem’s Internet connection. Routers have emerged as the de facto way to build a home network due to the plug-and-play convenience they offer.

    Integrated Router and Modem Devices

    Several network equipment makers sell combination units that integrate the functions of a broadband router and broadband modem into a single physical unit.

      Sometimes called home network or residential gateways,  these units are often acquired by Internet providers and sold or rented to customers as part of their subscription.  Other than being physically integrated into one device, the functions of the router and modem are identical as when they are two separate devices. Some consumers prefer the convenience of integration, but other customers prefer to keep freedom of choice and flexibility to replace or upgrade their routers separately from their modems.