Wats the difference between fractional distillation and refining in petroleum industry???

Distillation separates crude oil into a variety of groups by boiling them until they vapourise. The vpour is allowed to cool at different temperaturesin a huge tower. At each temperature, a number of hydrocarbons become liquid and separate out. These are called fractions and this process is known as fractional distillation.

Whereas, Separation of various components of petroleum is called refining.