Flash distillation is a continuous distillation process used to separate components in multicomponent systems that boil at very high temperatures. It works by suddenly vaporizing an entire liquid mixture by passing it from a high pressure zone to a low pressure zone, relying on differences in vapor pressure and boiling points between components. Unlike regular distillation, flash distillation is not efficient for obtaining pure components but can separate components that would be difficult to distill through conventional heating methods due to their high boiling points. The document provides an introduction to the basic principles and methodology of flash distillation.