what benefeits you gain from light armor and what you gain from heavy??

I always say heavy for an all out warrior as why would you sacrifice the extra protection?

Light for a warrior who is also relying on the addition of magic or stealth.

For those that aren`t warriors, i`d say robes or clothes.

Light armor doesn't slow you down as much and makes less noise, so it's better for sneaking. Heavy armor provides stronger defense, but you will use more stamina.

All of the differences can be negated through various means though. Such as the steed stone, muffle and perks to make armor weightless.

Continuing on what Khan said, what it really comes down to is aesthetic & exclusive enchantment bonus preferences(Daedric Artifacts, for example. Ebony Mail is a Heavy Armor Chest/Legging piece, and has an enchantment that can be found nowhere else in the game).

Armor Cap can be easily reached for almost all pieces of armor, and there are mechanics to erase the less relevant distinctions between the two types.

Any set of armor can reach the armor cap. Its all about what you like best.

armor caps at 547

The differences really only come into play if you don't do any smithing.

in the vanilla game, mechanically, the only real difference is that Light armor gets you more stamina, and thus is the only armor worth using from an optimization standpoint