What’s the difference between a modem and a router?

Is a modem the same thing as a router? Learn what defines each, as well as what we mean by gateway, and why these words are often used interchangeably.

What is a modem?

A modem connects your home to the internet through the provider’s network. It acts as a translator to pass information back and forth between your home network and the larger public network, forming what’s called a WAN (wide area network). The modem has a public IP address that is assigned automatically and serves to identify it on the internet. A modem on its own typically has an Ethernet connection port but no WiFi. However, in many cases, additional parts of the home network (such as a wireless router) are combined with the modem in the same package.

What is a router?

A router shares information back and forth between devices, forming a LAN (local area network), which it then connects to the modem, letting all the devices in the network use the same internet connection. The router can be housed in the same box as the modem, or it can be separate in some cases. It connects to multiple devices using Ethernet cords or, in the case of a wireless router, a WiFi radio signal. The router assigns a local IP address to each device on your network and directs the flow of data. This means your devices can talk to each other so you can share files, print wirelessly, and more. Finally, the router provides security protections such as firewalls and parental settings, allowing some degree of control over data access.

What is a gateway?

In the past, both a modem and a router were needed to get internet access to more than a single computer. Today’s technology has evolved so that we now have what is called a gateway. The gateway combines the function of both the modem and the router into one handy device. That way there's only one device to plug in and configure. All CenturyLink "modems" are really these gateways, which provide internet access, create a WiFi network in your home, and offer security protections plus various customizable settings. 

So what do we call it?

Most internet users today still think of their internet equipment as a modem, so we often use that term on our Support Center. In some cases, we refer to it as a router when talking about WiFi. And, if you contact tech support, agents will typically refer to it as a gateway. The bottom line is that, for CenturyLink customers, though they mean different things technically, any of these three words can be used to talk about your internet equipment.

Looking for even more technical details? Read this.