The word “modem” is a contraction of the words modulator-demodulator. A modem is typically used to send digital data over a phone line. This standard was for the first modems which were invented in the 1960 to allow terminals to connect to computers. However, in today’s world these transmissions are typically done over Ethernet cables or fiber optics.
Today the modems are much faster and are connected to your ISP (internet service provider). Your computer no longer sends characters, it now sends TCP/IP stack forms. The ISP in turn transmits these forms to the world wide web and you are connected to the internet and are able to send and receive information and brows the web.
Cable modems are widely used today and are among the fastest methods of connecting to the internet. These speeds can be well over 10mbps. These cable modems compress data into a 6 megahertz signal that is sent along a dedicated portion of the cable line. The modems also decode the signal as the signal is reaching the modem.
A modem interprets the information that is received from the internet and converts it by the use of the A/D converter (Analog/Digital Converter). This interpretation sends the message in the form of 1s and 0s to your computer which in turn is translated into an image or text on your computer that you can understand.
The main advantage of cable modems over DSL is the speed. I’m sure if you are old enough to remember dial up internet you will defiantly remember how long it took to simply connect to the internet and to even so much as surf the web was not a pleasurable experience. It took forever to go from one site to the next.