The exact values of these stats change with level and sometimes with class, so precise numbers aren't possible in the general case like this.
All definitions are from the Caracter page in-game.
Absorption - more absorption means more damage mitigated when you shield an attack.
Accuracy - reduces chance to "miss" your opponent. Once you have 0% chance to miss, reduces opponents defenses instead.
Alacrity - makes spells channel, tick, or cast faster.
Armor - Reduces kinetic and energy damage by a constant %.
Critical - increases chance for a critical strike.
Surge - increases the bonus % on a critical strike.
Damage Reduction - Just a listing of the various types of damage on your character, currently
Defense - increases parry and deflect rates
Power - provides a bonus to tech and force abilities. (Your abilities scale with Power. Your class' main stat provides Power as one of its benefits. Depending on class, this could be Aim, Strength, Cunning, or Willpower)
Shield - base chance to shield.
Glance Rating - increases chance to shield