Essential oil is a concentrated hydrophobic liquid containing volatile chemical compounds from plants. essential oils do provide a lovely aroma when used in diffusers, they also provide specific compounds found naturally in plants and plant parts, including bark, leaves, flowers, and even the roots and seeds. There are many different types of products on the market. The line of products that I recommend is Young Living Oils, and I use these in my Aiken, SC, home. For more information, please visit roll-with-me.com