A mug is a sturdily built type of cup often used for drinking hot beverages, such as coffee, tea, or hot chocolate. Mugs, by definition, have handles and often hold a larger amount of fluid than other types of cup. Usually a mug holds approximately 12 fluid ounces (350 ml) of liquid; double a tea cup. A mug is a less formal style of drink container and is not usually used in formal place settings, where a teacup or coffee cup is preferred. Purple is a color. It's purple.