Being a Newbie, I have thousands of questions.

Right now my question is about measuring sugar.

I understand SG, how to use a Hydrometer, and how to calculate ABV.

I also understand the BRIX to SG relationships. Brix=261.3*(1 - 1/
sg),

But degrees Brix and SG seem to accomplish much the same tasks. They
both seem to be methods for measuring sugar in suspension in liquid.
And from this, you can calculate several things, and you can time
various winemaking steps.

As a new winemaker, my instinct says to learn to both methods of
measurement and both scales, but to be honest, i don't know why. While
a hydrometer reads SG and a refractometer reads degrees Brix, to me,
they are both indicators of the same thing.

So, what method should i use?