The hard-disk recorder (HDR) is the central component of the modern digital audio studio. The most basic feature of a high-quality HDR is the capability to record and play multitrack/multichannel digital audio at various sampling rates. However, with the addition of software amenities such as non-linear and non-contiguous editing operations, support for a variety of soundfile formats, and audio digital signal processing via plugins or built-in modules the HDR is no longer simply a more or less sophisticated record/playback device. At this point it has become a digital audio workstation (DAW).