Digital video recorder
A DVR (Digital Video Recorder) is an electronic device that records television programs onto an internal harddrive for later viewing. They have become popular in recent years due to their ease of use, high-quality (digital) recording, and the ability to easily skip commercials. The most popular brand currently on the market is TiVo.
A DVR must be attached to the cable box (via an S-Video, coaxial, or RCA cable) to receive the cable signal. Some cable companies incorporate DVR functionality into their cable boxes, eliminating the need for this connection. A secondary attachment called the IR (infared) blaster will connect from the DVR to the IR receiver on the front of the cable box. This allows the DVR to change the channel on the cable box, exactly like a remote control does.
The DVR must also must have an Internet connection that it may access at times in order to download the latest program listings. Though DVRs may be set to record at a certain time on a certain channel, the preferred method is to use the DVR's operating system. A user can search for a program and then choose their desired showing from the search results. They can also peruse a grid displaying all programs, and select from that. Many DVRs have a "Season Pass" functionality that will record a particular program on every airing, eliminating the need to set the DVR more than once.
The amount of programming that can be stored by a DVR is restricted by the size of its internal harddrive. Most devices will delete older programming to make room for newer programming. Other than that, there is no technical restriction why a user cannot keep a program on the DVR for as long as they want.
Though the activity of recording television shows for viewing at a later time (time-shifting) is usually considered fair use, many media producers have taken actions to restrict the functionality of DVRs. This includes eliminating the output capabilities, so that programs can not be transferred off the DVR onto another medium, such as a regular computer or video cassette tape. The most controversial is the broadcast flag. Programs would contain a hidden signal that would control the digital usage of the recording, such as deleting it after a period of time, eliminating the ability to skip commercials, or even not allowing it to be recorded at all.