Difference Between A Modem And Router

When you sign up with an internet service provider, they sometimes bring a modem and a router (two devices), or a modem-router combo (one device with both functions). These terms are mistakenly used interchangeably which can cause confusion during tech support calls where staff might ask you to restart your “modem”, but some can’t tell the difference between the routers and the modem, which compounds the issue.

What are modems?

Modems are used to bring internet from internet service providers (ISPs) into homes and offices. They exist since the “dial-up” era and before wireless internet became a standard, and they are still used in this day and age because their basic functionality is still needed.

It takes the analog signal used carried by a cable or a wireless transmission and demodulates it to a digital signal that can be understood by computer. It also takes the digital signals from a computer and modulates it into analog signals, thus the term “modem” which actually stands for “modulator/demodulator”.

What are routers

As their name implies, a Router “routes” the signals received from the modem to multiple other devices (mobiles, laptops, smart devices etc). In essence their purpose is to make a single internet connection subscription available to multiple devices.

Most of the time the term “router” is used to refer to “wireless routers” in everyday speak, but in reality routers can either route your internet signals through wired connections via the ethernet ports, or through wireless signals which our phones and tablets typically rely on.

However routers can also sometimes wear multiple hats. For the most part, a lot of our modern day wireless routers are combinations of multiple devices which includes:

1. A router that routes data packets to multiple devices;
2. A switch that lets you connect ethernet cables to multiple devices such as computers. These switches are sometimes sold by itself which are used to add more wired connections in case the bundled ports aren’t enough. These switches require a connection to a modem or a router in order to have internet connectivity, kind of like extension cords but for the internet. However they still “work” if network connectivity is all you need, like setting up a local network for printers or a LAN party where internet connectivity isn’t required;
3. A wireless access point (AP or Wi-Fi AP) which is what helps devices without an ethernet port connect to the internet, such as your smartphone, tablet, or smart home gadgets and appliances like speakers, TVs, refrigerators, and so on;
4. In some cases some routers also come with a modem built into it, which means that you won’t need to get a separate modem and router which is useful if you’re trying to reduce clutter and even cost.

A typical setup

A typical setup that you might find in your home, homes of others, or offices usually looks a bit like the diagram below.

How modems and routers affect Internet performance

Do modems and routers affect internet speed? Putting aside other considerations such as the network card used on your computer, the number of users using the internet at home, or the number of people subscribed to the same ISP in your apartment complex, modems and routers can definitely play a role in affecting internet speed.

Supported Frequencies

You might see on the packaging of routers that they mention support for 2.4GHz/5.0GHz. These are the wireless frequencies that are supported by the router.

Take for example how older (wireless) routers only support 2.4GHz frequencies. This means that even if you have a very fast internet plan, you won’t be able to take full advantage of it, versus routers that support 5.0GHz frequencies. At the same time one shouldn’t automatically assume that 5.0GHz frequencies are “better”.

The downside to the 5.0GHz frequency is that it has a shorter range, so if your device is positioned far away from the router, you might actually lose the signal. However modern day routers usually come with support for both frequencies, with some models being smart enough to automatically switch between 5.0GHz and 2.4GHz frequencies depending on how far you are.

Wired vs. Wireless

There is some debate about whether a wired or wireless connection is better in terms of speed. While routers are great at distributing internet throughout your home, there is evidence that proves that going wired does result in better networking speeds in general, but there are some scenarios in which that might not necessarily be true.

These days modem and router makers are built with new hardware that has been upgraded to better support faster internet speeds. However if you have an older modem/router that supports up to a certain speed (say 100Mbps), but your internet plan is much faster than that (1Gbps), then regardless of whether you go the wired or wireless route, your theoretical speeds will remain capped at 100Mbps due to the limitations of your hardware.

Prioritizing

As tempting as it is to ensure that every single device in your home or office is as fast as possible, sometimes it isn’t always necessary. For example if your primary computer needs to deal with the downloading and uploading of large files, then maybe placing it closer to the router or using a wired connection will help with performance.

If you’re a competitive gamer in which milliseconds in latency can make or break your performance, then maybe directly connecting your PC or console via a wired connection might be a good idea.

However for certain devices that consume very little data, then maybe speed shouldn’t be that big of a priority, such as internet-connected clocks, smart speakers, smart refrigerators, and so on.

At the end of the day, as you can tell from the various scenarios we’ve laid out above, there are differences between modems and routers and how you’ve set them up that can potentially affect your speeds. However at the end of the day, these chains of connections (Internet<–>Router<–>Modem<–>WiFi<–>Devices) are only as strong as their weakest link.

Tyler Lee
Categories: Computers
Tags: modem, routers