A hard disk recorder (HDR) is a system that uses a high-capacity hard disk to record digital audio or digital video. Hard disk recording systems represent an alternative to reel-to-reel audio tape recording and video tape recorders, and provide non-linear editing capabilities unavailable using tape recorders. Audio HDR systems, which can be standalone or computer-based, are typically combined with provisions for digital mixing and processing of the audio signal to produce a digital audio workstation (DAW).
Direct-to-disk recording (DDR) refers to methods which may also use optical disc recording technologies such as DVD, and Compact disc.