Modem vs. Router: What Each Does and How They Differ

How are modems and routers different?

Router with cables connected to it

Tetra Images / Getty Images

The difference between a modem and a router is that a modem connects to the internet, while a router connects devices to Wi-Fi. 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, and you'll save money by purchasing equipment, rather than paying a monthly fee to an ISP.

What Modems Do

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.

Modem on a desktop
MysteryShot / Getty Images

ISPs rent modems to subscribers for a monthly fee, but 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.

1:14

What Is a Modem in Computer Networking?

What Routers Do

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.

Wireless router in the foreground, person using a laptop in the background
Kittichai Boonpong/EyeEm / Getty Images

Some ISPs offer routers for rental, but 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.

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.

What Are Mesh Networks?

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, so 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.