If you have ever played WoW before the spec changes that occurred in Mists of Pandaria I think (I only played during that expansion). You had your class, e.g. Warrior and as you leveled you spent points in your talent/skill tree. Skills and talents were broken up into 3-4 categories. What you chose determined the role you filled.
So you are still a warrior, but you might be a tank (protection), or DPS (arms, fury). Specs.
