An essential oil is a fragrant oil that is a concentrated liquid containing volatile chemical compounds or oils from plants. 

Essential oils are the oil of the plant from which they were extracted, such as oil of clove.

They are extracted from the plant material through steam distillation and named after the plant from which they are derived. Essential oils can be defined as either products or mixtures of fragrant substances or as mixtures of fragrant and odorless substances.

Some examples include

Peppermint Oil..Lemon oil...Cinnamon oil..Lemongrass oil. ...Clary sage. ...Lavender oil. ...Tea tree oil. ...Eucalyptus oil...Rosemary oil.