Cable modems connect a home network to the residential cable line from an Internet service provider. These modems plug into a broadband router on one end, usually with a USB or Ethernet cable, and into a wall outlet on the other. Cable Internet providers rent these modems to subscribers, but you can also buy one. Here's how to find one that fits your needs.

The Data Over Cable Service Interface Specification (DOCSIS) standard supports cable modem networks. All cable broadband Internet connections require the use of a DOCSIS-compliant modem.

There are three major versions of DOCSIS modems:

A D3 modem is suitable for modern cable internet. Although prices for new D3 modems can be higher than for older versions, the price difference has become considerably smaller in recent years. D3 products have a longer lifespan than older versions and can provide faster connections than older modems.