More complicated than this sadly, but a necessary topic to understand. This is part of signal flow. VERY shortened 2 hours lesson (Literally, 2 hours of lecture on these topics every time I teach mixing, and many students still don’t understand it truly after that and it is only after they play with it for hours afterwards they start to get it).
By default, your signal will flow from the top of the processor box to the bottom. It will flow through each pre-fade plugin in turn, then through the fader, then through each post fader plugin. What this means is that the fader does not affect the input signal going into any pre-fade plugin, but will only affect the output of all those prefade plugins. And the fader will affect the input of any plugin directly post fade, which in turn those plugins affect the signals of those following them.
Often times people use post fade sends to send to effects busses (Reverbs, Delays, etc.) so that if they bring the fader down, the end result will be a natural tailing off of the reverb as the inputs signal is no longer feeding it. Likewise people often use dynamics processors pre-fade so that they are acting on the signal before the fader, and they can use the fader to control the overall level of the signal after these processes for an easier and cleaner mix.
These are both guidelines, and when you truly understand the affect of signal flow in the DAW (Much like a console) you can break these when you want to, but it is best to understand it first.
I hope that answered your question to some extent.