Essential Oil vs Fragrance Oil

What is the difference between essential oils and fragrance oils. Basically essential oils are naturally derived, and fragrance oils are synthetically derived. Essential oils are made from natural things, like a rosemary essential oil is made ONLY of rosemary, unless they are cheap. We only use essential oils that are made only of one thing. Fragrance oils are synthetically derived and, for the most part, are blends of different scents. They are made with many different chemicals. In the US companies are not forced to put all of the ingredients of a fragrance in the ingredient list.