Abilities (Nanotrites) in RAGE 2 are specific skill sets that you can earn and use while in combat.
Abilities or Nanotrites are powers that turn you (Walker) into a super human. You earn more abilities by finding Ark's (some Ark's will even have unique weapons) around the world in different regions while wandering the Wasteland. Each ability is different and you can choose or swap them out anytime to cater to your playstyle. Abilities range from regeneration of your health, a barrier to protect yourself from bullets/missiles and a grav-jump that acts as a double-jump.