Cable Modem

Cable Modem (Cable Modem), is the hardware that connect your PC with a cable TV connection. This cable TV network can be used to connect to the internet with a maximum speed of 27Mbps downstream (to the user's download speed) and 2.5 Mbps upstream (upload speed of the user). In order to use a cable modem, the computer must be equipped with an ethernet card (Ethernet card).
Network

Inside the home network, a cable from "Cable TV" using coaxial cable and installed a "dividing line" (splitter) cable. After the cable from the network (cable network) through the splitter, cables channeled into two channels, one to the TV and one to cable modem. From the new cable modem to the ethernet card and then to the computer.

Source :http://id.wikipedia.org/wiki/Modem_kabel