What is the difference between distillation, distillation under reduced pressure and steam distillation ?

Explanation

Distillation is employed in case of volatile liquids associated with non-volatile impurities.
Distillation under reduced pressure is carried to purify liquids which decompose at their boiling point temperatures.
Steam distillation is done for the steam volatile associated with water immiscible impurities. For more details, consult section 12.38.