Differences between +DEF & Damage Reduction

What's the difference between having +Defense versus Damage Reduction?
Also same question applies to Attack+ versus Addition damage..

Well, For damage reduction = fixed amount of dmg decrease.
For def increase still be consider dmb reduce but will varies example(HS Def buffs)

You have like 995def without ring and the buff will take 10% of it and round off to the nearest value.

When you increase your defence with 2def ring it will make some minor difference like addition -1.

*the buff spells for DEF are calculated if you have +DEF than Damage reduction..

For Short, +def varies with total def during buffs..
but dmg reduction rings does not.