How Does Cable Internet Work?

Cable internet service uses the same coaxial cable network as cable television to provide your home with internet.

First, your internet service provider sends a data signal through the coaxial cable, or coax cable, into your home—specifically, to your modem.

The modem then uses an Ethernet cable to connect to your computer or router, which is what gives you access to high-speed internet. If you choose to use a router, you can then broadcast a Wi-Fi signal throughout your home.

Cable internet service providers transmit data between servers using this coaxial cable, and since TV itself takes up only a small portion of the cable’s bandwidth, it leaves room for internet service to work within the same network.

These cable networks stretch all across the country, and there are even undersea cables that reach between water-separated areas. Plus, cable internet can spread speeds evenly among individual users. It also means that if you pay more, you have access to more bandwidth, which means faster speeds.

Here's a quick look at the cable internet providers we recommend the most:

To help wrap your mind around cable internet service, it’s useful to define some of the jargon.

Your bandwidth is your network’s capacity to transmit data. Think of your coax cable as a tube that transfers data like a hose transfers water. A coax cable can transmit enough data for both TV and internet service. And to get faster speeds, you need to get more bandwidth.

A modem is an electronic device, usually a box, that receives data from the cable provider’s network and delivers it to the home. The modem can connect directly to a computer or to a router to distribute Wi-Fi.

In order to connect your computer to the internet, you also need a network card (sometimes called a “network interface card,” or NIC). These are either plugged into expansion slots on your computer or integrated into the computer already.

A network adapter is the built-in form of a network card, meaning your computer has it integrated without needing an expansion slot.

Your internet service provider will send a data signal through the coaxial cable or coax cable to your modem. A coaxial cable helps cable internet service providers transmit data between servers. 

An Ethernet cable connects your modem to your computer or router. Ethernet cables can connect other devices directly to the internet (instead of Wi-Fi) for a more reliable signal.

A router is a device that spreads your modem’s direct signal into a Wi-Fi signal. And it can also serve as an Ethernet hub for other devices. Modems and routers can be combined and sold as one unit, often referred to as a gateway.

When it comes to measuring internet speeds, the most common acronym you’ll see is Mbps. It’s how much data (in megabits, or Mb) transfers within one second.

You might also see speed measured in Gbps, or gigabits per second, since cable internet is starting to break into gigabit download speeds. 1 Gbps equals roughly 1,000 Mbps.

Cable download speeds range anywhere from 1 Mbps to 1,000 Mbps (1 Gbps). The national average is around 100 Mbps.

Upload speeds aren’t quite the same, though, usually ranging from 1 Mbps to 50 Mbps.

Cable internet typically has higher connectivity speeds than dial-up or DSL (and those have more limited bandwidth than cable, as well).

Slow upload speeds are one limitation of cable internet. The old networks weren’t designed with internet uploads in mind. Providers would have to rebuild with newer cables, but we expect fiber internet (and other new tech) to take over instead.

Cable, satellite, and fiber-optic internet download speeds are similar to a certain point. But satellite signals are less direct, meaning they can run into interference during transmission.

Fiber speeds can reach above 300 Mbps, even up to 2,000 Mbps, and fiber’s upload speeds can range from 50 Mbps to 2,000 Mbps. Fiber networks are expanding, but they’re still not quite as available as cable internet.

With its direct cables and reliable signal, cable remains a good way for most people to get high-speed internet.