Cable TV companies provide broadband Internet access over their networks (primarily to residential customers) by installing a device called a cable modem in customers' homes.

A cable modem can run at high speeds, with a maximum download speed exceeding 8 Mbps. However, because the networks are shared, most users experience speeds of around 1 to 1.5 Mbps downstream and 256 Kbps (or less) upstream, depending on how many people are using the shared network at a given time.
The speeds are comparable to DSL.

A cable modem connects a customer's personal computer to a network node that is shared by about 350 to 700 customers (with the expectation that only a fraction of its customers will use the system at any given time). Each shared network in turn connects to the computers at a cable company's main office, which are connected to the Internet backbone. In many instances, the cable company acts as its customers' ISP.

When a customer orders broadband cable service, the cable company sends a technician to the person's home to install the cable modem. The technician places a splitter on the side of the house to separate the coaxial cable line that serves the cable modem from the line that serves the customer's TVs.

The technician then runs another coaxial cable line from the splitter to the cable modem, which connects to the customer's computer through an Ethernet card or a USB (Universal Serial Bus) port.