A digital cable TV activation system from the OpenCable project of the CableLabs research consortium (www.cablelabs.com). Introduced in 2003, the CableCARD contains the customer's account information as well as the channel assignments and decryption algorithms used by the cable provider. The CableCARD is housed in a Type II PC Card module, and after July 1, 2007, all new set-top boxes in the U.S. were mandated by the FCC to support CableCARDs.

No Separate Set-top Box and More Accuracy
When a set-top box is used, depending on the type of box, TV set, connection used and digital format transmitted, additional and unnecessary video processing may take place in the chain from the set-top box to the TV. However, the CableCARD can also be plugged directly into TVs, DVRs, digital media servers and PCs that are "Digital Cable Ready" and eliminate the set-top box. For example, when a Digital Cable Ready TV decodes as well as scales the original signal from the cable company, it eliminates the possibility of repetitive conversions. In addition, the decoding process can reveal data that enables more accurate up and down scaling (see upconvert).

S-CARDs, M-CARDs and tru2way
The Single Stream CableCARD (S-CARD) provides one tuner for viewing one channel. Video-on-demand and other interactions are supported, providing the TV is bi-directional. It is a common misconception that two-way capability was added with the CableCARD 2.0 specification; however, this capability is a function of the TV. The "tru2way" logo certifies that the TV is a two-way CableCARD device.