These satellite receivers have one or two CI Slots. These slots are the same as the PC Card slots that you have on your laptop computer.  A Common Interface (CI) Module is inserted into this slot, and the smart card fits into the CI module. The CI modules are available in several encryption types, Irdeto, Seca and Viaccess being the most popular in Australia. CI Receivers will usually work on other Free to Air (FTA) Services. Some CI receivers are available with a Personal Video Recorder (PVR) function.
The PVR will allow you to record programs onto the built in hard drive, for viewing at a later date. Recordings can be scheduled, and more advanced PVRs will allow you to record several channels at the same time, while vieiwing a previously recorded program. Trick functions suck as slow playback, fast playback, reverse playback, and tagging segments on the recording are aslo avalible. Hard drives of 100s of megabytes are available, with about 40 hours per 80 giga byte record rates.