fractional distillation and distillation有咩唔同

Fractional distillation is the separation of a mixture into its component parts, or fractions, such as in separating chemical compounds by their boiling point by heating them to a temperature at which several fractions of the compound will evaporate. It is a special type of distillation.
Generally the component parts boil at less than 25°C from each other under a pressure of one atmosphere (ATM). If the difference in boiling points is greater than 25°C, a simple distillation is used.

Purpose of Distillation:
1. To separate the solvent from a solution of a non-volatile solute (e.g. to separate water from an aqueous solution of sodium chloride)
2. To make the concentration of the low-boiling-point fraction higher in a liquid mixture (e.g. to make the concentration of ethanol higher in a aqueous-ethanol mixture)

fractional distillation ,
is used to seperate the mixture in which the component substances with different boiling point and all / most of them are required ~
while distillation is for simple use ....maybe only one substance is required ~