A digital video recorder (DVR), sometimes referred to by the merchandising term personal video recorder (PVR), is a consumer electronics device or application software that records video in a digital format to a disk drive, USB flash drive, SD memory card or other local or networked mass storage device. The term includes set-top boxes (STB) with direct to disk recording facility, portable media players (PMP) with recording, recorders (PMR) as camcorders that record onto Secure Digital memory cards and software for personal computers which enables video capture and playback to and from a hard disk. A television set with built-in digital video-recording facilities was introduced by LG in 2007,[1] followed by other manufacturers.DVR adoption has rapidly accelerated in recent years: in January 2006, ACNielsen recorded 1.2% of U.S. households having a DVR but by February 2011, this number had grown to 42.2% of viewers in the United State