Understanding Combat "Ratings"

[Omens]

Not only concerning PvP but also PvE...

Here is the Codex resume of all Combat related "Ratings" :

-Critical Rating: Increases the crit chance of Melee, Ranged, Force and Tech damage and healing effects. Builds based on achieving critical hits and heals, particularly those whose crits generate additional buffs, benefit greatly from Critical Rating.

-Surge Rating: Increases the magnitude of all crits, both damage and healing. Builds based on achieving critical hits and heals, particularly those whose crit magnitude is improved with skills, benefit greatly from Surge Rating.

-Accuracy Rating: Increases the chance of successfully hitting an enemy with a Melee, Ranged, Force or Tech effect. Builds based on lightsaber and blaster combat, particularly playstyles focused on fighting higher toughness and higher level targets, benefit greatly from Accuracy Rating.

-Power Rating: Increases the damage and healing dealt by Melee, Ranged, Force and Tech effects. Builds based on reliable and sustained damage and healing output benefit greatly from Power Rating.

-Alacrity Rating: Increases the activation and channel speed of abilities. Builds based on activated and channeled abilities benefit greatly from Alacrity Rating. Alacrity Rating does not affect instant abilities.

-Defense Rating: Increases the chance to defend against Melee and Ranged attacks. Builds based on survivability, particularly those who favor avoidance, benefit greatly from Defense Rating.

-Shield Rating: Increases the chance to shield a Melee or Ranged attack with your personal shield generator. Builds based on survivability, particularly those who favor steadily lessened incoming damage, benefit greatly from Shield Rating. Shield Rating has no effect on characters not equipped with a personal shield generator.

-Absorption Rating: Increases the amount of damage negated when an attack is shielded with your personal shield generator. Builds based on survivability, particularly those who favor steadily lessened incoming damage, benefit greatly from Absorption Rating. Absorption Rating has no effect on characters not equipped with a personal shield generator.