Codex text
Each ability tree contains active abilities, upgrades, and passive abilities.
Active abilities have diamond-shaped icons. They can be mapped to your hotbar and then used in combat.
Upgrades are attached to an ability and make it stronger.
Passive abilities have circular icons and are permanent boosts to your character that are always active.
XBox 360/XBox One...
Use LS to navigate the trees and inspect an ability's details.
PC...
Drag with left mouse button to navigate the trees and hover over an ability to inspect its details.
PS3/PS4...
Use L to navigate the trees and inspect an ability's details.