The difference between fragrance oil and essential oil

What's the difference between fragrance oil and essential oil? 

Often see online friends say that the use of essential oil configuration perfume and do aromatherapy, what is the difference between essential oil and fragrance oil, as I know, perfume is made with fragrance oil right? 

Fragrance oil is a synthetic concentrated aromatic oil that mimics the smell of fruit and natural spices. It's an artificial perfume. Mostly used in the manufacture of food, cosmetics and cigarettes. 

Essential oil is a volatile aromatic substance extracted from flowers, leaves, stems, roots or fruits of plants by steam distillation, extrusion, cold leaching or solvent extraction. 

To put it simply, the price of essential oil is high, the output is small, and it is mostly used in cosmetics such as beauty and perfume, while the Fragrance oil is synthetic, most of which are cheaper and added to food.