How is crude oil separated into fractions?

Crude oil is seperated using a method called fractional distillation. The hydrocarbons that make up crude oil have different boiling points, so when the crude oil is heated, each compound evaporates at a different temperature. The hydrocarbons then condenses into seperate fractions. Compounds with the lowest boiling points travel to the top of the coloum since they evaporate first, and vice versa. This means the column is hottest at the bottom, and cooler at the top.