Dexterity
The dexterity attribute is a measure of a character's agility and expertise with weapons. Dexterity is required to use dexterity-based equipment and skills. Dexterity-based skills tend to emphasize speed and movement superiority, either by making you faster, or by making your enemies slower.
Dexterity also grants certain passive bonuses:
Passives
There are passive skill nodes that grant additional dexterity or a combination of bonuses including dexterity.