People are usually very peculiar about the glassware in which their cocktail is served. Glasses with different shapes and depths are used for different cocktails. But have you ever wondered why they can't just serve every cocktail in the same glass? Is there some kind of logic behind the glassware chosen for each drink? Like is there any procedure or some science involved? 

Well, this video by PBS Idea Channel answers all your questions. 

Ek Gillasi? Do Gillasi? Teen Gillasi? Chaar?