Modem vs. Router: What's the Difference?

Modem and router are two most commonly used external devices in the computer. Both have fundamentally different purposes, though they are used in digital communication . The main difference between the two devices is that a modem lets you connect to the internet (ISP), while a router distributes that connection to different devices . This means that a modem is your gateway to the world wide web, while a router is a central hub for your all devices such as mobile phones , laptops, desktop computers, and smart TVs. Normally, the router in our homes are performing both the functions of a ROUTER and a MODEM that is why most users cannot differentiate.

Modem vs Router: Understand the Difference


A modem (short for modulator/de-modulator) is your gateway to the internet connection . This means that a modem is a device that provides access to the internet connection. Modem works in Layer2 of Open Systems Interconnection (OSI) Model and data is carried in form of frames. A Modem has only 2 ports one for connecting to ISP and other for connecting a computers or router.

Why Modem?

The main purpose of Modem is modulation of an analog signal to digital signal and vice-versa. Because there are two different types of signals are used between a computer and ISP. Since a computer only reads digital signals while the signals from ISP's are analog signals. As analog data comes from the internet, the modem converts(demodulates) the incoming analog signal into a digital signals so that computer can understand it. Also, it modulates the out going signal into analog signals.

A Modem Establishes and maintain a dedicated connection to your ISP to give you access to the internet connection. By connecting a modem to your router (instead of directly to a PC), all devices connected to the router can access the modem , and therefore, the internet connection. A modem can work without a router, delivering internet connection to a single PC.

Modem vs. Router: How Do They Differ?

Types of Modem

  1. Dial-up Modem
  2. DSL Modem
  3. Cable Modem
  4. Mobile broadband Modems
  5. Half Duplex Modem
  6. Full Duplex Modem
  7. Four Wire Modem
  8. Two-Wire Modem


A router is a device that is used to connect networks with different subnets . This means that a router is what brings all your home devices together. It is a "bridge" between your modem and your devices . While connecting to a router provides access to a local area network (LAN), it does not guarantee access to the internet connection. In order for devices on the network to connect to the Internet, the router must be connected to a modem.

Why Router?

A router is a layer 3 device that routes traffic between networks. Even though you have only one physical connection from your ISP to your Modem , a Router lets you create multiple networks so that you can create multiple devices wirelessly and simultaneously. The main function of a router is to handle the traffic between various networked devices. It keeps track of their Media Access Control addresses (MAC addresses) to ensure information gets sent correctly. It has a feature called NAT (Network address translation) which translates public IP that received from the ISP to Private IP . All the devices connected to the router will get private IPs. These private IPs will be translated into public IP whenever required.

Difference Between Modem and Router

Types of Router

  1. Wireless Router
  2. Modem Router
  3. Bridge Router
  4. Distribution Router
  5. Core router

When you are going to have multiple devices that need to access to the internet that is why you need a Router instead of Modem. If you just plug the device's network cable directly into the modem, then you will be able to access the internet. So, technically you really don't need a router If you want only one device to access the internet.

Combined Router and Modem

While the modem and router are usually separate devices, in some cases, the modem and router may be combined into a single entity . This type of hybrid device is sometimes offered by ISPs to simplify the setup process. Using separate devices offers more flexibility in what you can do with your network and lets you make sure you're using the best quality devices you can.

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