Distillation is a separation technique used to separate components of a liquid mixture by a process of heating and cooling, which exploits the differences in the volatility of each of the components. The liquid that is obtained by performing the condensation of vapor is called the distillate. Distillation is carried out at the solvent's boiling points. Boiling takes place when the vapor pressure is equivalent to the atmospheric pressure.
Separation of the components of the mixture takes place better in case of the higher relative volatility of a liquid. On supplying heat to the liquid, the vapor boils and then condensation takes place.
This technique works in a very similar way to simple distillation, but a fractionating column is used to get a temperature gradient, cooler at the top and hotter at the bottom. The column is used to control the temperature at which the distillate is being collected, allowing different liquids in a mixture to be separated, each turning into a vapor and being cooled and condensed in the condenser at their own individual boiling points.
Steam distillation is a separation process that consists in distilling water together with other volatile and non-volatile components.
Vacuum distillation or Distillation under reduced pressure is a type of distillation performed under reduced pressure, which allows the purification of compounds which are not readily distilled at ambient pressures or simply to save time or energy. This technique separates compounds based on differences in their boiling points.
There is a piece of evidence that humans were using the distillation process since 3000 BC (approximately). This process is used to make distilled water.