Should I compress more or adjust volume?

[del64]

I am fairly new to production, about 5 months now, but I still have a lot to learn.

I understand that compression is used to help competing frequencies to be distinguished, however, I was wondering would it be in best practice to compress the audio sound to lower or actually adjust the volume of the track.

thanks

[Tarekith]

That's probably the most vague compression question I've ever seen. Maybe this helps clear some things up on it:

http://tarekith.com/assets/pdfs/DynamicsControl.pdf