the principle is to make whatever you do in one area of the timeline immediately happen in another, on any track, automation, anything. Sort of like creating shared copies but on a larger, project-wide scale.
For example, there are three chorus’ in my song.
on the timeline i have three marker track areas designated as “chorus” “chorus 2” and “chorus 3”
when i change something, like a fade or the position of a sample, it immediately does it in all the other chorus areas which i have designated as shared areas.