Q:
Defense rating and health?
A:
The Defense stat is combined with the stat Toughness to determine your armor, the more armor you have the less direct damage you take. It has has no effect on your health pool, in order to increase your health pool you need Vitality.
Defense rating is kinda like Item level. It basically tells you how good the item is, but honestly that is up to you.
http://wiki.guildwars2.com/wiki/Armor#Defense_Ratings
Those are the max you can get, which are found in exotics. I’m not too sure what causes it to go up and down, but I would assume its how defensive it is (armor/health/toughness)
I’m fairly sure it just gets added to your “Armor” stat, which reduces incoming direct damage.
@Uriel: Thanks! Also, thanks to Deified — your link help me find this:
http://wiki.guildwars2.com/wiki/Armor_
…which reiterates Uriels post. The Armor stat, which determines how much incoming damage is reduced, "…is equal to Defense plus Toughness attribute… "
I’m glad it helped, see you around SoR.