In WAR, the term archetype refers to one of the four general types of careers available. War is divided into four archetypes. These archetypes each have attributes that give advantages over one another. In Warhammer Online the four archetypes are Tanks, Melee DPS, Ranged DPS, and Support/Healers. This is a chart of the various Careers and their archetypes.
Each army has exactly one playable career for each archetype (see table), and each archetype performs a specific main role, although different careers of the same archetype may play slightly differently. For instance the Sorceress is a Ranged DPS archetype career, however, her play mechanic (called "Dark Magic" - causing her to have a chance to hurt herself the more harmful magic she casts) is very different from the Shadow Warrior (also a Ranged DPS), who has a stance-based mechanic of gameplay.
Archetypes also have an advantage over another Archetype. This plays in very well when balancing the careers.