Fractional distillation is a process that separates mixtures into their individual parts or fractions by heating them to the boiling point of each component and condensing the vapors, allowing different chemical compounds to be isolated based on their differing volatility and boiling points. It involves heating a substance to the point where its components vaporize and then cooling the vapors to condense them back into liquid form, with the heavier fractions requiring higher temperatures to vaporize collecting lower in the distillation apparatus.