I'm just checking myself about the use of FADERS vs VOLUME plugin

[sjs94704]

As I am just learning mixing, I'm gonna take a shot at this and say that I think that when I want to control the overall volume of the song from start to finish that I would use the volume plugin. For example, in my song template that I use, there is an INSTRUMENT BUSS track that all of the instruments are sent to. We all know that there is that spot of -18 db that we are (at least I have been told) is the 'sweet spot'.

So, I use the Volume plugin to be sure that the song stays very close to -18 db.
I realize that this idea might be subjective and that people might have varying opinions on this idea. I also know that there is no 'rule' that says it must be at -18.

It is only when I want the volume of certain instruments or maybe a vocal to go up or down in just part of the song that I would use the FADERS.

Do I have this right? If not, I would be grateful for some clarification.