Mixing
Multi-Track Analog and Digital Audio can be routed through a Mixer either prior to being processed to a computer hard disk or afterwards when the file(s) are being edited. The Mixer can can also function as an intermediary device between several analog and digital peripheral hardware used to record and process digital audio.
Mixing (either with software applications or hardware device) is combining many tracks or inputs into one or two (maximum) outputs (no matter how many tracks you have recorded, when they are played back they will automatically be combined into 2 digital channels stereo). One can cue or solo the sound, which can then be combined with other tracks. Various effects can be applied with the mixer depending on its capabilities. The more recent devices also allow for the processing of audio at levels close to 96 KHz sampling rate and 24-bit resolution, which exceed Redbook CD standards.
As you add recorded tracks, the volume of each individual track may have to be reduced so that the total volume of all tracks combined does not exceed the 16-bit rate (if that is the standard of your software). If it does, you will get a condition known as clipping, which is when the dynamic range of the waveform of the sound exceeds the processing capabilities of the mixer application.