This chapter describes the principles of digital audio recording and editing systems, including an introduction to signal processing resources. It offers a brief introduction to the elements of a typical DAW and how they relate to each other. Crossfading is similar to butt joining, except that it requires access to data from both incoming and outgoing sound files for the duration of the crossfade, and involves some simple signal processing. Data storage media used with a DAW system, such as hard drives , need to offer at least a minimum level of performance capable of handling the data rates and capacities associated with digital audio. Digital recording tape is thinner than that used for analog recordings; long playing times can be accommodated on a reel, but also thin tape contacts the machine's heads more intimately than does standard 50-micron-thick tape which tends to be stiffer.