Defence and armor stats

Hi everyone

i need a little help with defence and armor stats, as not sure how it works or if it’s broken.

the only stat I can see is armor and no defence, so how is armor worked out as my character has 63.7% with plus 8.5% and 56.4% plus 8.4%.

the defence on my mods are defence 48, 37 and 47 which is 132 plus the character normal defence?

with defence % of 25% from set plus 11.75, 10.63 and 8.61 which would be 55.99% from mods 

any help would be greatly appreciated