This video is a tutorial for a music producing software program called Ableton Live 8. In this tutorial he shows you how to apply effects to effects to audio using the audio effect rack function. The way this function works is by being dragged into the bottom of the program and being applied as a place to hold various effects. Using the effect rack you can modulate and manipulate the sound waves in the effect. This is a very convenient tool to have in Ableton because it allows you to have more than one effect in the same place making it easier to control.
Have an iPhone? Check out all 200+ new features coming in iOS 13.