Damage reduction vs damage deflection?

What is damage deflection? Is that like damage return? I was looking at the ability "Alune's Grace" and noticed seperate stats for damage reduction and damage deflection... Just wondering what the difference was, and whether or not deflection acts like a damage return on the enemy. Like thorns or Spiked Carapace.

Deflection = % of damage dealt to you returned to attacker
Reduction = % of damage dealt to you reduced
That's the difference.