Anyone know what this means on the microprofiler?

Honestly have no idea what most of the stuff on the microprofiler even means. All I know is big bar = lag. Anyone know the cause of these bars shown below?

Im no professional on the microprofiler, though im pretty sure the lengths of the bar is how long the process takes per frame. The length can depend on how big your game is, how many scripts are running, and other stuff.

Yeah that much I know. I just don’t know what the bars are indicating of what is causing lag.

Maybe this old video might help you a bit: