One of the most common ways people connect to the internet today is through cable modems. A cable modem is a device that has the ability to deliver high speed internet connections through a cable. In fact, in most places, the cable that is used to transmit this internet access is that same cable used to transmit a household�s Cable Television. One can obtain such an internet service by paying for a subscription to a cable company that supplies it. Today, most cable modems closely resemble the design of DSL modems. The cable internet and television transmission, known as a CATV signal, needs to reach this cable modem to supply that household with internet. This is accomplished through a coax cable. The coax cable that is used will have a high level of bandwidth. This will include space for upstream internet service used for uploading and downstream internet service used for downloading. It will also include enough space to transmit the cable television feed simultaneously with internet service. Usually, a cable modem does not need to be bought separately from a cable internet subscription. It is usually included as part of the service and will be sent to a customer free of charge after he or she has purchased a subscription. Some companies, however, require a customer to return the machine to the internet service provider if that customer chooses to end their contract. Usually, cable modems exist as pre-configured external modems. However, in other cases, the modem may come as part of a set top box. This is the unit that is used the descramble cable signals. Such signals are scrambled to prevent non-subscribers from stealing the service. Certain computers can also be purchased with an internal cable modem. However, these usually have to be specially purchased from a computer retailer. Such internal modems may be compatible with a cable internet provider�s services. However, it is a good idea to inquire about this beforehand. There are certain advantages to choosing one�s own cable modem. Different cable modems on the market include different features a customer may find appealing. One possibility is a cable modem that comes with a built-in router that allows an internet connection to be shared between multiple computers in a home or office.