What is the different bit ween glass and cristal glass

Question

star hotels using for the drinks glasses there is some of glasses some one cristal

Answer 1

Usually a 'crystal glass' just means that there are no impurities in it to affect the flavor or aroma; when appreciating fine beverages even a slight addition from the glass's material can overpower the subtler elements.

It's most important in bottle and decanters, as that's where the liquor spends the most time.