like Warriors have Fury (dps), Arms (dps), or Protection (tank). Paladins have Retribution (dps), Holy (healing), or Protection (tank). Priests have Holy (healing), Discipline (healing), Shadow (dps) etc.
If you wanted to be a Fury Warrior you picked talents down the Fury talent tree.
All Warriors have stances you can switch between which are Battle stance, Defensive stance, Berzerker stance.
Battle stance for sustained damage. Defensive stance for when you're taking damage. Berzerker for rage dumping/burst.
Stance dancing is like sitting in Battle beating them down and switching over to Defensive when they pop cool downs and you want to mitigate damage.