Industry expert Tony O'Lenick compares and contrasts natural vs. essential oils.
Essential oils are any concentrated, hydrophobic liquids containing volatile aroma compounds from plants. They are also known as volatile or ethereal oils, or simply as the "oil of" the plant material from which they were extracted. An example is oil of clove.
The term essential indicates that the oil carries a distinctive scent or essence of the plant, not that it is an especially important or fundamental substance. Essential oils do not have any specific chemical properties in common, beyond conveying characteristic fragrances; they are generally extracted by distillation.
Natural oils are triglycerides in which the glycerin is esterified with three fatty acids. They are the main constituent of vegetable oil and animal fats. Chain lengths of the fatty acids in naturally occurring triglycerides can be of varying lengths, but 16, 18 and 20 Carbons are the most common.
Natural fatty acids found in plants and animals are typically composed only of even numbers of Carbon atoms because of the way they are bio-synthesized from acetyl CoA. Bacteria synthesize odd- and branched-chain fatty acids.