CableCards are devices that plug into a slot built into a digital TV or other device that allows digital cable services without a cable box.
We have a CableCard plugged into our TiVo that allows us to watch digital HDTV without a digital cable box.
The CableCard provides the same security and de-scrambling function as a cable box.
It stores subscriber information and codes for unlocking and viewing scrambled digital cable signals.
The Card is about the size of a thick credit card and is meant to replace a cable box, but it does not yet replicate all the cable box functions.
The Cards cannot be used for services that require two-way communication, such as accessing your cable company's interactive programming guide or purchasing pay-per-view programs.
The main reason to get a CableCard is convenience. You can remove one component from your home entertainment system and you’ll have one less remote control to misplace.
It is cheaper to manufacture the Cards than cable boxes and the Cable companies say we should see the benefits from that, but time will tell.
You could pick up a card and plug it in to your TV set, but most cable companies require a technician to install the card to make sure it works with the TV.