PVR is a storage system, as shown in the picture below, to store broadcasting programs incoming through diverse channels such as cable, satellite broadcast, digital television, after compressing with MPEG-2, into HDD in a computer. It has diverse functions like searching, replaying, clear imaging, performing replay and record simultaneously.

EPG provides all broadcasting schedules visible through digital satellite as well as airwave and cable broadcast and also enables viewers with simple reserved recording and series recording after their observing schedule table and details in it. In case of cable television, though there is difference of channel number according to living area, a viewer can automatically download visible information day by day if and only if he inputs his living area name where the default was set up and the name of manufacturing company of cable set top box. This also enables a viewer to deal with television programs easily like Internet search and to watch his favorite programs in his favorite time.

PVR provides diverse additional services concerning program recording. For example, a viewer can edit his own program when selecting the programs he wants to record from website. He can only select a popular sitcom, a pro-baseball game, a movie casting his favorite actor, cooking program, and so on. PVR floats a program schedule on television and make it possible for a viewer to reference detailed information and to record on reserved or in real-time.

These functions might look crumpled, though, they must be awesome discovery when we remind of current VCR system to need viewers troublesome manipulation.

When you are interrupted by phone ring or should go to restroom while watching climax of your favorite sports game, you only have to push on stop button. From the time on, broadcasting signals starts to being recorded automatically into hard-drive.

if you return and push on replay button, you can watch the video recorded from the timepoint when recorded broadcasting signals were stopped. Moreover, you can watch again real-time programs and replay in slow motion capture, and also skip boring scene. This core function of PVR is Time Shift function rather than Live Pause, which enables a viewer to record and replay now watching broadcast programs. These functions have a good meaning for they also enables a viewer to control watching television programs itself.

In order to record video signal into HDD, the signal inputted by analog method should be converted to digital signal through ADC(Analogue to Digital Converter). This digitalized signal, by MPEG-2 encoder, is compressed as a form of MPEG-2, a digital television standard, into HDD. At the same time, the recorded program is decompressed by MPEG-2 decoder, and converted to analog signal through DAC(Digital to Analogue Converter).

Video signal converted to analog signal is output through an output terminal in PVR, this signal is monitored on television screen through an A/V input terminal in television and the video screen is presented, which is much like that was inputted through an analog input terminal at first. For in this way the signal brings HDD out from inside PVR, this broadcasting signal enables temporary stop and replay whenever viewers want.

The purpose of PVR is to perform recording as a basic function, and PVR+DVD product is already spread in the market. Also a variety of combined products are expected to be displayed in after-market. Here, most noticeable thing is the change of broadcast environment that mass media are being diversified recently (cable, satellite, internet broadcast). PVR should have local storage for program recording, and network functions for EPG information and program search so that it is the most powerful candidate to step to home-server.