What Is A Modem and How Does It Work?

Aaron Paul updated on Nov 11, 2022 to Knowledge Center

Over the years, people's communication through computer devices has undergone drastic changes. It was only a couple of decades ago when people required telephone cables just to be able to connect to the internet.

It was usually done with the help of a modem device. Which brings us to today's topic; what is a modem? In this article, we'll explain what a modem is and how it works. Besides that, we'll talk about the types of modems and how it compares against the modern router that we use.

Thus, we'll explore a few key aspects of this technology besides talking about the differences. So, let's dive right into it.

What Is A Modem?

A modem is a device that allows two or more devices to communicate using telephone lines. Modems are necessary for the internet to work. They convert digital information from one device into analog signals.

So that the data can be transmitted over the telephone line and then converted back into digital information once it reaches its destination. The word 'modem" itself was driven from Modular-demodulator. Which is a type of hardware that converts data.

So, how does it convert data? Its purpose is to convert digital data into analog systems so that it can travel through wires from one modem point to another. Hence, it used telephone cables to transmit information—i.e. the early shape of the internet.

However, the invention of the Modem dates back to the early 1950s. Later, over the years, until the late 1990s, the technology went through many evolution phases. The final setup was around 56k dial-up products.

How Does Modem Work?

The Modem works on a simple and basic technological base. Understanding the Modem's working process is a lot easier than today's technology. That's why it's important to understand that the basic pillars of a Modem include the following:

  • Devices that connect through a coax cable connection, i.e., the telephone wire
  • Uses an IP or online address provided by an ISP (internet service provider)
  • The Modem takes digital signals from the cable and ISP, then converts them into analog signals and vice versa
  • It uses the Wide Area Network (WAN) as a base to assign a public IP address, which helps it identify computers on a network

But to simply put, a modem converts digital data into analog and vice versa to establish communication between two ends (server to computer and back).

Types of Modems

Modems come in many shapes and sizes. However, there are three main types of modems, and they are used universally. While the dial-up Modem might be outdated, these three main types are still thoroughly used, which are:

A cable modem is the one we discussed earlier, used through telephone lines or WAN. Whereas DSL or Digital Subscriber Line is a broadband-based modem. Lastly, a fiber modem is one that employs fiber optics and cables to transmit data.

Modem VS Router

The Modem is cable-based, whereas routers are generally referred to as wireless internet-providing devices. But their differences are far more than those two simple lines. Yet, you can still define their differences in two lines, such as:

  • The Modem connects you and brings the internet to your home
  • Routers bring the internet to your devices and connect them to the internet

These are the two main differences between the two technologies. Another key difference is the fact that a Modem comes with a public IP address, whereas routers assign a local IP address. Lastly, modems use a WAN network, whereas router creates their own LAN (local area network).


There you have it, folks, the difference between Modem and routers and the definition and types of modems. While one can claim that it's an outdated technology, others would claim it's simply evolved into something else today—and both won't be wrong.

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