Whole butter is mostly butterfat, plus water and milk solids. When you melt it gently, those parts separate: foam rises, clear golden fat sits in the middle, and milky water and solids sink to the bottom.
Clarified butter is that clear fat on its own. The milk solids are what burn first in a hot pan, so removing them lets the butter take more heat. Ghee is closely related. It is usually cooked longer, until the solids brown, which gives a nuttier flavour.





