Modem vs. Router: How Do They Differ?

What's the difference between a modem and router?

The difference between a modem and a router is that a modem connects to the internet, and a router connects devices to Wi-Fi. We reviewed both to take away the confusion about how they work and to help you choose which device you'll need for your internet needs.

Modem vs Router
  • Decodes the signal from an ISP.

  • Connects directly to the internet.

  • Doesn't set up a local network.

  • Is not responsible for Wi-Fi.

  • Establishes a local network.

  • Creates and manages Wi-Fi.

  • Splits an internet connection to several devices.

  • Does not decode the signal from an ISP.

  • Requires a modem to connect to the internet.

It's easy to get the two devices mixed up if your internet service provider (ISP) rents both to you as part of an internet package. Knowing the difference between a modem and a router and how each work can help you be a better consumer. You'll save money by purchasing equipment, rather than paying a monthly fee to an ISP.

Modem Pros and Cons

  • Connects to an ISP.

  • Compatible specifically with the ISP.

  • Converts the signal from the ISP to a universal one that a computer can use.

  • Can't create a local network.

  • Doesn't run Wi-Fi.

  • Doesn't connect multiple devices to the internet.

A modem connects the source of your internet from your ISP and your home network, whether you use a cable provider such as Comcast, fiber optics from FIOS, satellite such as Direct TV, or a DSL or dial-up phone connection. The modem connects to the router—or directly to a computer—using an Ethernet cable. Modems are different for each type of service; they are not interchangeable.

ISPs rent modems to subscribers for a monthly fee. However, cable modems are available for sale at relatively low prices. Monthly rental rates are around $10 extra per month. If you plan to keep the same service for a year or more, buying a cable modem that costs about $100 quickly pays for itself. FIOS-compatible modems are hard to come by, so in that case, it's worthwhile to rent one from Verizon. Some ISPs lease both modems and routers.


What Is a Modem in Computer Networking?

Router Pros and Cons

  • Creates a local area network (LAN).

  • Splits an internet connection to several devices.

  • Hosts Wi-Fi.

  • Runs a firewall.

  • Connects to a VPN.

  • Can't connect directly to the internet.

  • Doesn't decode the signal from an ISP.

A router connects to a modem and creates a private network in a home, office, or business such as a coffee shop. When you connect a device to Wi-Fi, it connects to a local router.

Routers connect smart devices, including smartphones, smart speakers such as Amazon Echo, and smart home products such as light bulbs and security systems. Wireless routers also stream content to laptops and mobile devices through Netflix, Hulu, and similar services, without using cables.

Some ISPs offer routers for rental. To get the latest technology, it's worth buying one. Buying a wireless router means you can choose the model that's best suited for your home or office or has advanced features for gaming and other activities if you need them.

In some scenarios, one wireless router isn't sufficient to cover an entire home or office due to a vast space or one with a complicated layout, multiple floors, or impenetrable walls. To avoid dead zones, purchase range extenders that connect to the router and expand its reach. However, that usually means less bandwidth in areas near the extender, which translates into slower browsing and download speeds. That's when investing in a mesh network might make sense.

A Wi-Fi mesh network consists of one primary router and several satellites, or nodes, that relay the wireless signal from one to the next, like a chain. Rather than extenders that communicate only with the router, mesh network nodes communicate with each other, and there's no loss of bandwidth. The signal is as powerful as if you were next to the primary router. There's no limit to how many nodes you can set up, and you can manage it using a smartphone.

Whether you need a range extender or a mesh network depends on the size of the space and how much bandwidth is required.

Do You Need a Modem and a Router?

You need a modem and a router to set up a home network. If you're connecting a single computer to the internet with a wire, you can use only a modem. There's no case where you can use just a router. You'll always need a modem to decode the signal from your ISP.

When you want to speed up your network, the router is usually what you want to focus on. It has bandwidth limits, and it distributes the signal to all your devices. Your router creates and manages your Wi-Fi.

The modem usually doesn't cause a slow connection. Generally, you'll get one from your ISP, and they'll give you one suitable for your subscription. If you plug in your computer directly to your modem and run a speed test, you can tell whether you're getting your advertised internet speed. If not, contact your ISP. There may be a connection issue, or your modem may be outdated. In this case, they may swap it out for a newer model.

What Does a Modem Look Like?

Modems typically look like small black, skinny, square boxes. Frequently, they have between two and four antennae but not every modem includes an external antenna. The images at the top of this article give you a good idea of what a modem looks like but every manufacturer uses a different style and shape.

Modems will also include between two and four ethernet ports, one or two USB ports, and range between six and nine inches wide to six to eleven inches long and about two to three inches high.

Five different types of modems lined up to show how different they can look.
Modems come in all shapes and sizes.

Modem and Router Combo Devices

There are also modems with integrated routers that perform both functions. These modems can be rented from your ISP or purchased directly. These combo devices might include a VoIP function if you have a cable, internet, and phone package.

Combination devices are not usually the best option. If one part breaks, the whole thing is useless, and you can't upgrade one device at a time. Still, if you don't need the latest and greatest tech, buying a combo modem and router is convenient.

  • Which is better: modem or router?

    If one must make a comparison, the modem wins. A modem is always your main gateway to the internet, whether it's a modem connected via a coax or fiber optic cable or a modem in your smartphone. A router's function is to distribute (or route) that internet connection to other wired or wireless devices in your Local Area Network (LAN). Essentially, you can plug one device into your modem and have internet access. However, you can't connect a device to a router and have internet access—unless you've connected the router to a modem.

  • When do I need a modem vs. a router?

    You need a modem to access the internet. Then, you'll need a router to distribute that internet access to your devices (computer, smartphone, smart TV, etc.). Routers can also connect devices within your network; for example, a router enables you to connect your printer to your PC. An internet connection is not required to connect devices within your network.

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