Whats the difference from a glass sword and orc sword......the heavy material weapon seems to always do more damage so why ever use a light material weapon?

I think it mainly matters in relation to smithing perks. With the right light armor smithing perks you can make them equal or better. Of course same goes for the heavy smithing/heavy weapons.

The reason why people want to use light weapons is for character consistency and the desire to spend some perk points elsewhere. Keep in mind that these perks also enable one to make light armour.

Also, heavier one-handed weapons use up more stamina with power attacks.

do light weapons swing faster than heavy weapons in game?

I can't remember how vanilla Skyrim treats weapons, but with SkyRe lighter weapons (even of the same weapon type) are able to be swung faster than their heavier counterparts.

does anyone know if ingame vanilla skyrim if lighter weapons swing faster than heavy i handed weapons?

if not i wonder why i ever used weapons such as glass when i could have been using dwarven,orcish i handed weapons....i always upgraded to ebony and dadric i handed weapons later in the game...personally i dont like dragon weapons.

http://www.uesp.net/wiki/Skyrim:Weapons

No. It relies entirely on weapon type. You should use Google more often.

Unlike armor, weapons are all in the same linear progression of quality that goes iron->steel->orcish->dwarven->elven->glass->ebony->daedric (some special cases such as skyforge weapons, and DLC materials slot in various places somewhere in that progression).

Stock, the heavier the material, the more damage or protection you will get, at the cost of more encumbrance. Although perks can offset that. However any material can be improved with Smithing to the cap. So, it comes down to what material you want your character to use and plan your Perks accordingly.

Exactly.

Depends on you're perks for sure. For base vanilla each type is a step-up from the last but you could change that with smithing perks.