Though a digital interface with a defined protocol, MIDI is not a digital audio interface, but rather exists for the purpose of interconnecting electronic musical instruments and their associated devices (such as effects and mixers). MIDI allows electronic instruments to be controlled externally, either by a master keyboard or by a computer, and carries control information relating to pitch, duration, velocity etc. than binary sound data.

On a multimedia computer, MIDI files produce music through the PC's internal soundcard, but do not usually store real-world digital audio sounds such as the human voice, except in cases where sound is sampled in short bursts for looping purposes. As a result, MIDI files do not contain vast amounts of data and therefore consume less disk space than digital audio.

One advantage of digital audio over MIDI is that since PC hardware monitors audio input on a regular basis (i.e. at the chosen sample rate ), information is constantly transferred to the disk - regardless of whether there is an input signal present or not. MIDI data arrives at the disk in a far less constant manner - there will be no data arriving in quiet passages, while note-heavy passages carrying vast amounts of MIDI control data causes the computer's processor to work harder.

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