What does defence mean? Work of some stats

Defense is armor, like offense is damage.

Defense equation works like this:

Mitigation= Armor/(Armor+level*10)

EDIT: so at level 70, in a unit with 170 armor, that +30 means you go from 19.5% damage reduction to 22.2%

Yeap, I understand that Offence applies to both physical and special damage, as well as defence applies both to Armor and Resistance.
Ok. What does mitigation means?
I am 70 lvl and have 150 Armor. My mitigation according to your formula is:
150/(150+700)=150/850~0,1765
Does it mean that 150 defence for 70 lvl makes physical damage 17,65% lower?

"Triqui;130354" wrote:

EDIT: so at level 70, in a unit with 170 armor, that +30 means you go from 19.5% damage reduction to 22.2%

OK. I got this, thank you. Looks trustworthy. But it brings other questions:
1) We've talked about formula for Armor...
a) Does it mean that +30 Defence is +30 Armor and +30 Resistance?
b) Is this formula applied to Resistance as well?

2) Isn't it wrong that the higher level you are, the lower bonus from Defence Up Leader abilities you get? Since your level is in a denominator, it will make you mitigation lower when it is higher.