What is a Modem? Types and Examples You Need to Know

By Tibor Moes / Updated: June 2023

What is a Modem? Types and Examples You Need to Know<br />

What is a Modem?

Whether you’re a professional, student, or gamer, you rely on the internet to work, study, and have fun. We all rely on the internet so much that our day can be ruined should we be left without the web.

Every component, including your mobile device or Wi-Fi router, speaks a different language. But a modem is the translator that makes that connection possible.

Read on for more details on modems, their types, and examples you should know about.


  • A modem, or “Modulator-Demodulator”, is a crucial networking device that transforms digital data into analog signals (modulation) and vice versa (demodulation) for transmission over communication lines, such as cable or telephone lines.
  • Modems allow for efficient data exchange between devices, enabling internet access and communication services. Their functionality is distinguished by transmission speed (bps), and types include DSL, cable, or fiber-optic modems.
  • Though modems are often integrated with routers in a single device for convenience, they serve distinct roles: modems connect your network to your Internet Service Provider (ISP), while routers distribute that internet connection to your devices.

Don’t become a victim of cybercrime. Protect your devices with the best antivirus software and your privacy with the best VPN service.

Modem Technology Origins

Modems appeared in the 1960s. Their existence made it possible to connect terminals to computers using a telephone line. Today, the word “modem is mostly used to describe a broadband modem that offers high-speed internet services.

The best way to depict the idea behind a modem is to look at its name, which is actually a contraction of two words: modulator demodulator.

Modems normally send digital data over phone lines. In the computer + telephone network + terminal equation, there are two separate modems that make communication possible. One between the computer and telephone network, and another between the telephone network and the terminal.

The first modem serves to send data (or modulate it) into signals understandable to the phone line. The second modem serves to demodulate data into digital signals. You also have wireless modems that use radio signals to convert digital data.

How a Modem Works

On the surface, the work of a modem is relatively simple.

This device receives information from your ISP through different channels.

  • Optical fiber
  • Phone lines
  • Coaxial cables in the home

The type of channel the modem connects to depends on the service provider.

Once the modem receives data, it creates digital signals. This is when your router comes into play. The router pushes that signal out to your connected devices, such as a computer or phone. The router uses Wi-Fi or a wired Ethernet cable to do that.

At this point, you may wonder, why doesn’t the router simply communicate with the ISP to make the connection possible? Why do we need the modem?

It’s because the ISP and the router speak different languages. The signal types each of them transmit are unintelligible to one another. That’s why they need a mediator: a modem.

Now that you understand how a modem works and why it’s necessary, let’s explore the different modem types out there.

Modem Types

Different modem types can be used to access the internet at home or in the office.

Digital Subscriber Line (DSL) Modem

The digital subscriber line modem uses telephone lines to provide a high-speed internet connection. This is a more expensive modem compared to most others. The DSL can also connect to your phone line. However, there’s a difference in voice communication.

Many people confuse the DSL modem with a dial-up modem (more on that below), but there’s a crucial difference. The DSL modem lets you use your internet connection while it’s connected to the telephone line, while the dial-up doesn’t have that functionality.

Cable Modem

Cable modems use cable TV networks to provide high-speed access to data. Modern-day cable modems come in the form of external devices that can connect to a computer or PC using an Ethernet card (10 BASE-T) along with twisted-pair wiring.

Cable modems are very popular. They are the best choice for an internet connection today.

Satellite Modem

As its name states, a satellite modem offers an internet connection using satellite dishes. Satellite modems transfer the input data to output radio signals to execute, and vice versa. This is the most expensive modem option because it offers a better and more stable internet connection.

Wireless Modem

A wireless modem lets you access the internet without relying on cable wires from your internet service provider to allow the internet connection.

Internal Modem

The internal modem plugs into expansion slots that exist in a computer. Different from external modems, these devices don’t offer a series of display lights that let the user know of different modem states. The user uses a communications program for that.

External Modem

An external modem is a standalone modem that doesn’t feature a router. Sometimes it can be attached to a computer using a USB cable, Wi-Fi, or Ethernet cable. However, this is rarely the case.

Most often, this device is attached to a separate router so it can share a connection with multiple devices in the office or home.

Router/Modem Combination

As the name states, the router/modem combination features a modem contained inside a router. This allows multiple devices or computers to connect to a single network. This combination is commonly used today because it eliminates the need for a network to have a separate router and modem.

Integrated Modem

Integrated modems are located inside computers, and only allow a single device to connect to the internet.

Dial-Up Modem

Much like the DSL, dial-up modems rely on a cable to connect to a telephone line. The difference is that the DSL lets you use your phone line while being connected to the internet, while the dial-up doesn’t.

This is a more affordable modem because it comes with zero installation costs. Also, dial-up modems come with a lower monthly fee. You can use telephone modems in just about any home with a telephone network.

Dial-up modems used to be popular when the internet first came into being. But since the emergence of high-speed and broadband internet, hardly anyone uses this type of modem anymore. Broadband modem solutions are more popular today.

Modem Speed

The speed of a modem is an extremely important factor to consider when opting for this device. A modem should be able to handle the ISP’s provided speed. Otherwise, it can result in connection issues.

Modern-day internet service providers offer incredibly high internet speeds. For example, if you have a download speed of 300 mbps, you need a modem that can match that. If your modem can only handle 1,000 mps, your internet will be too slow to handle the load.

Similarly, if you know your internet speed potential is limited to 300 mps, it’s not worth investing in modems that offer a faster speed, as it simply won’t be used to its full potential.

How to Choose the Right Modem

Choosing the right modem can be a challenging task.

Now that you’re well aware of different modem types, you’ll have an easier time deciding on the one you should use. The device connection and internet speed are of course some of the main features to consider.

Compatibility will depend on your computer or software on your device. All modems have descriptions on the boxes or online that mention modem compatibility. You can find those in the “system requirements” section.

The upload and download speed is also different from one modem to another. If you use the internet to upload pictures or videos or download tons of music and movies, it’s best to go for faster speeds.

Security is an important element to consider. You can find important security information on the modem’s box or in its online description.

Ultimately, you can ask your internet service provider for advice on which modem pairs best with your specific package. That way, you’ll use both the download and upload speeds offered by the provider, as well as the modem, to their full potential.

Modem Examples

Maybe your internet service provider has too high a fee for modem rentals each month. This is a good enough reason to consider purchasing your own device. Most of the time, a modem will pay for itself in the first year.

Here’s an overview of the best modems that work with most ISPs and internet plans.

Motorola MB7621

Motorola MB7621 is one of the best cable modem solutions on the market. It offers a reliable internet speed of up to 650 mbps. Many internet providers rank this modem as the best solution given its digital tuner that allows for a stable connection without breaking the bank.

This modem has a 1 gb Ethernet port that is compatible with computers, Wi-Fi routers, HDTV, game stations, and video streaming devices. Note that to use this modem, you’re required to have a cable internet service.

The installation of this modem is fast and easy, and it can be completed independently with the use of the quick start guide.

Its compact design enhances cooling, takes less space, and prolongs its lifespan.

Motorola MB8600

This modem is a great choice for users that have gigabit internet services. It’s a well-designed product with a generous warranty, but with a bit higher price range compared to the MB7621 model.

The built-in capabilities of this modem give it super-fast internet speeds for all cable services. It can be paired with just about any Wi-Fi router out there, including Mesh, Whole Home Wi-Fi, Google Wi-Fi, Orbi, and others. There’s also a 10/100/1,000 gigabit Ethernet port for connecting single devices. This can include a Mac, Windows computer, router, HDTV, or a game station.

The Active Queue Management boosts the internet stability and provides faster page loading for web traffic and interactive apps, like gaming or video conferencing.

Note that this model doesn’t come with a wireless router or telephone call features. However, it does have a proactive network security system that protects the user from malicious attacks.

Netgear CM500

Netgear CM500 is a great modem if you’re looking for a budget solution that doesn’t need more than 650 mbps/1 gbp to operate. This is more than enough speed for a fast download of videos, gaming, and online TV show streaming.

You can connect any Wi-Fi router to its Ethernet port. The 1 gigabit Ethernet can also connect to a computer or separate Wi-Fi routers.

Installation is fairly simple and doesn’t require using CDs. There’s an installation guide inside the box so everyone can perform the setup with ease.

If you’re a regular internet user that enjoys occasional gaming, this is arguably the most budget-friendly way to save money on modem fees and have long-lasting, uninterrupted service.

ARRIS Surfboard S33

The Surfboard S33 is an approved modem for service providers such as Cox, Spectrum, Xfinity, and many others. This beast of a modem supports speeds as fast as 2.5 gbps with the addition of an extra 1 gbp Ethernet port for another network. However, this modem doesn’t include Wi-Fi. There’s also no support for cable digital voice service.

You can still connect this modem to any Wi-Fi router to get lightning-fast speeds and enjoy uninterrupted internet time. You’re looking at the fastest modem from ARRIS’s Surfboard lineup that comes with an effortless setup through a mobile app. Calling your internet service provider to activate the modem is a thing of the past with this modem.

The convenience does come at a price, as this modem is more than double the price of some of the previously mentioned devices.

ARRIS Surfboard SB6190

If you liked the functionality of the previous ARRIS model but don’t need its super-fast speeds, you can get a more budget-friendly solution with up to 1.4 gbps download speed. The upload speed can get up to 262 mbps, but this mainly depends on your internet subscription.

Much like the previous modem, you can connect this one to your router or computer for even faster speeds. You can also stream HD videos and download channels to future-proof the device as the service offerings change at your local cable ISP.

Understanding the Modem World

Modems are indispensable in bringing an internet connection to our computers and other devices. This powerful box can transmit information necessary for the router in order to interpret signals coming from your internet service provider.

It’s important to know the differences between popular modem types so you can choose the best one for your particular needs. Should you need extra help with modem features, you can always ask your ISP for advice.

How to stay safe online:

  • Practice Strong Password Hygiene: Use a unique and complex password for each account. A password manager can help generate and store them. In addition, enable two-factor authentication (2FA) whenever available.
  • Invest in Your Safety: Buying the best antivirus for Windows 11 is key for your online security. A high-quality antivirus like Norton, McAfee, or Bitdefender will safeguard your PC from various online threats, including malware, ransomware, and spyware.
  • Be Wary of Phishing Attempts: Be cautious when receiving suspicious communications that ask for personal information. Legitimate businesses will never ask for sensitive details via email or text. Before clicking on any links, ensure the sender's authenticity.
  • Stay Informed. We cover a wide range of cybersecurity topics on our blog. And there are several credible sources offering threat reports and recommendations, such as NIST, CISA, FBI, ENISA, Symantec, Verizon, Cisco, Crowdstrike, and many more.

Happy surfing!

Frequently Asked Questions

Below are the most frequently asked questions.

What is the difference between a router and a modem?

A modem is an essential element that allows the router to function properly. For the router to provide your home with an internet connection, it needs to understand signals that come from your ISP. The modem is able to interpret those signals.

Do I need a router or a modem?

Router and modem are different devices that work together to supply homes and offices with the internet. You can either use the two separate devices or rely on the modern-day combinations of both that function as one robust gadget.

What is a modem in short answer?

A modem is a device that translates signals offered by internet service providers so the router can understand them, making an internet connection possible.

Author: Tibor Moes

Author: Tibor Moes

Founder & Chief Editor at SoftwareLab

Tibor has tested 39 antivirus programs and 30 VPN services, and holds a Cybersecurity Graduate Certificate from Stanford University.

He uses Norton to protect his devices, CyberGhost for his privacy, and Dashlane for his passwords.

You can find him on LinkedIn or contact him here.