Editing CableCARD (section)

===Physical CableCARDs===
{{Multiple image
| direction = vertical
| image1    = Cable-card-cropped.jpg
| caption1  = A [[Scientific Atlanta]] (now [[Cisco Systems|Cisco]]) multi-stream CableCARD or "M-card"
| image2    = Cable-card-cropped-rear.jpg
| caption2  = The backside of the same card
}}

The physical CableCARD inserted into the host device is a [[PC Card]] type II that handles [[decryption]] of video and ensures that only authorized subscribers may view it. This is also known as a "[[conditional-access module]]" function.

There are two kinds of physical CableCARDs:
* A "single-stream" CableCARD (S-CARD) can decode a single channel at a time. The S-CARD specification was initially specified in the Host-POD Interface (SCTE 28) and POD Copy Protection System (SCTE 41) standards (often referred to as CableCARD 1.0) set of specifications.
* A "multi-Stream" CableCARD (M-Card) can decode up to six channels simultaneously. Multi-stream cards were specified in a separate document in 2003.

No actual M-Cards were released before the introduction of CableCARD 2.0, which combined and enhanced the CableCARD 1.0 and Multi-Stream standards.<ref name="opencable1">{{cite web |url=http://www.opencable.com/primer/cablecard_primer.html |title=CableCARD Primer |publisher=OpenCable |access-date=2009-09-16 |archive-date=2009-09-29 |archive-url=https://web.archive.org/web/20090929090609/http://www.opencable.com/primer/cablecard_primer.html |url-status=dead }}</ref>  M-Cards are [[backward compatibility|backward compatible]] with current CableCARD devices. In older CableCARD devices that do not support multiple streams, the card appears to be a single stream card. CE companies have long wanted M-Cards for their CableCARD 1.0 host devices in order to compete with devices that use multiple tuners. This is important for products such as [[Moxi (DVR)|Moxi]] and [[TiVo]] CableCARD [[Digital video recorder|DVR]]s, televisions with [[picture-in-picture]] and CableCARD-equipped [[personal computers]], which need to record one show while a user is watching another. To enable this without an M-Card, these products would be required to use multiple S-CARDs.