Automation (DAW)
Recorded movements of controls — volume, pan, effect parameters — that play back along with the music.
A mix rarely sits still. The vocal needs to come up in the chorus; an echo should only catch the last word of a phrase. This used to be done live, with several people at the desk each riding a fader, and a mix that went wrong in the final bar started over from the top. Neve's NECAM in 1977 recorded fader moves into a computer and let motors replay them, and since then a mix could be refined one move at a time.
In a DAW, automation is a breakpoint curve under the track. The modes kept their console names: read plays back, write overwrites everything, touch writes only while you hold the control, and latch keeps the last value after you let go. Nearly every plugin parameter can be automated, and MIDI CC is the usual way to record it from a physical knob.