How does Fractional Distillation Work?

Seperates crude oil into simpler more useful mixtures. Works because different hydrocarbons have different boiling points: 1) heated crude oil enters a tall fractionating column, which is hot at the bottom and gets cooler towards the top 2) vapours from the oil rise through the column 3) vapours condense when they become cool enough 4) liquids are led out of the column at different heights