When you heat water into steam that then is converted back into water, you are putting it through a process of distillation: purification by boiling and condensing vapors.
Distillation is a process of purification. Air and water are distilled to make them cleaner. Crude oil is distilled so that it can be used for various commercial purposes. Distillation involves a process of first heating to create vapor and then cooling to convert that vapor back to liquid form. Distillation is also the simplification of an argument to its most clear state. The distillation of an argument involves boiling it down so it's easy to understand.
