A cable modem is a hardware device that allows your computer to communicate with an Internet Service Provider over a landline connection. It converts an analog signal to a digital signal for the purpose of granting access to broadband Internet. A cable modem works by connecting a coaxial cable to a jack in the wall and then a Cat5 (Ethernet) cord from the modem to a computer or a network router. Network routers are used to share your Internet connection between multiple computers.
The picture is an example of a traditional stand alone cable modem from Motorola, there are also all in one modems that have a modem and router built into one box. If your modem only has one coaxial cable connection and one Cat5 connection, your modem is a stand alone modem and needs a router to share the connection.
Cable offers a significant speed increase in Internet performance when compared to a dial-up connection and is one of the fastest broadband solutions. Comcast and Time Warner are examples of cable Internet providers in the United States.
Tip: If the cable modem or Internet is not working, unplug the cable modem power cable, wait a few seconds, and plug it back in to reset the modem.