I am 100 in Sneak and I have all the perks. I just wanted to ask, what is the difference between the muffle and silence perks in the sneak skill tree and if I have both of these perks, can I sneak in full daedric armor as effectively as sneaking without any clothes on?

Both perks apply the 'muffle' effect. The lower perk applies it at 0.5, then the upper perk boosts that to 1.0. 1.0 is 100% muffled and you are completely silent regardless of your attire/armor. There is no benefit at all of having a muffle effect above 1.0. That means that once you have all the stealh perks, casting muffle or wearing muffle boots of no benefit.

So, if you have the Silence perk, you can wear Daedric armor with no degradation to your stealth.

Thank you so much i was also wondering what exactly does fortify sneak do and how is it different than muffle

Read up: http://www.uesp.net/wiki/Skyrim:Sneak#Remaining_Undetected