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

How are modems and routers different?

Router with cables connected to it

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The difference between a modem and a router is simple: a modem connects you to the internet, while a router connects your 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 your internet package.

Knowing what the difference is between a modem and a router and how each work can help you be a better consumer, and even save money by purchasing your equipment, rather than paying a monthly fee to rent them from your 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, like Comcast, fiber optics, like FIOS, satellite, such as Direct TV, or a DSL or dial-up phone connection. The modem connects to your router–or directly to your computer–using an Ethernet cable. Modems are different for each type of service; they are not interchangeable.

ISPs will rent modems to their subscribers for a monthly fee, but cable modems are available for sale at relatively low prices. Monthly rental rates are usually around $10 extra per month; if you're planning to keep the same service for a year or more, buying a cable modem that costs about $100 will quickly pay for itself. Note that FIOS-compatible modems are harder to come by, so in that case, it's worthwhile to rent one from Verizon.


What Is a Modem in Computer Networking?

What Routers Do

Routers connect to the modem and create a private network in a home, office, or place of business, such as a coffee shop. When you connect a device to Wi-Fi, it's connecting to a local router. That router brings all of your smart devices come alive, including your smartphone, but also smart speakers like Amazon Echo and smart home products (light bulbs, security systems). Wireless routers also enable you to stream content on your laptop or mobile device through Netflix, Hulu and the like, without using any cables.

Some ISPs offer routers for rental, but to get the latest technology, it's worth buying one outright. 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 that you can rent from your ISP or purchase directly. These combo devices might also include VoIP function if you have a cable, internet, and phone package. Combination devices are not usually the best option since 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 your entire home or office due to a vast space or one with a complicated layout, multiple floors, or impenetrable walls. To avoid dead zones, you can purchase range extenders that connect to your 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 right next to the primary router. There's no limit to how many nodes you can set up, and you can manage it all using a smartphone. Whether you need a range extender or a mesh network depends on the size of your space and how much bandwidth you require.