What Is an Internet Modem?

Connect to the internet and link to a router so you can set up a Wi-Fi network

Modems allow computers, routers, and other devices to connect to the internet. Learn more about what an internet modem is, how they work, and the benefits and drawbacks of different types of modems.

What Is an Internet Modem?

A modem is a device that plugs into your wall and brings the internet into your home. Most modems today use coaxial cables, the cylindrical cords that screw into the wall. You may be able to access the internet by connecting your computer with an Ethernet cable; however, if you want to set up a Wi-Fi network and link multiple devices to the web wirelessly, you'll also need a router.

What Does an Internet Modem Do?

Modems convert analog signals (from telephone, DSL, or cable lines) and change them to digital signals (and vice-versa) so devices can connect to the internet. In technical terms, the incoming analog signal is modulated, and outgoing ones are demodulated. That's why modem stands for modulator-demodulator.

You can connect your modem to a router using an Ethernet cable to create a Wi-Fi network. There are also modem-router combination units which are modems with built-in routers.

An illustration explaining what a modem is


How Do Modems Work?

Your modem receives data from your ISP (Internet Service Provider), allowing you to access the web. Since your router can't communicate with your ISP directly, the modem acts as the entry point for your Wi-Fi network to connect with the internet. How fast your modem transmits information depends on the hardware as well as your ISP package.

The main difference between modems and routers is that modems actually provide internet access while routers provide the Wi-Fi signal.

Types of Modems

Cable modems and modem-router combinations (aka Wi-Fi modems) have largely replaced traditional dial-up and DSL modems.

These modems connect to your wall through a coaxial cable (the same kind used for cable television) and have Ethernet ports for connecting computers and routers.

Cable modems are much faster than older connection technologies. If broadband internet isn't available where you live, then dial-up may be your only option, so make sure you get a modem that supports your connection type.

In areas where fiber-optic internet is available, you don't need a modem to access the web. Instead, you can connect a compatible router directly to your wall.

How to Choose a Modem

Your ISP may offer you a modem for a monthly fee, but it's often more cost-efficient to buy your own. Before you start shopping around, find out the recommended minimum specifications for your internet plan. You need the right equipment to make sure you're getting the internet speed you're paying for each month.

Here are things to look at when purchasing a modem:

  • Compatibility: Ensure the modem has all the ports you need (cable, Ethernet, etc.) to connect your devices.
  • Upload and Download Speeds: Check the minimum requirements for streaming videos, online gaming, and other tasks you do online to make sure your modem can handle it.
  • Security: Some modems offer advanced security features, such as built-in firewalls and parental controls.
  • Price: Modems range vastly in price depending on their capabilities. Higher-end models won't give you faster internet speeds if you don't have a comparable package with your ISP.

When selecting an internet package, first figure out your needs (speed requirements, number of users, etc.). Once you've picked out a plan, find a modem that meets or exceeds the maximum upload and download speeds. If you plan to upgrade your internet speed in the future, you might want to invest in a more powerful modem.

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