Essential oils, not to be confused with essential fatty acids, are named after the plants they are extracted from. Essential oils are usually extracted using distillation, and then concentrated.
Essential oils have many benefits, one of which is referred to as aromatherapy. Aromatherapy is based on the premise that the scents given off by the essential oils have mood altering, and possibly curative properties.
These oils can also be mixed with other base oils(olive oil, grapeseed oil) to make scented massage oils. A further use of these oils can simply be to freshen up a room by heating up the oil, vaporizing the oil or burning it in incense.