Essential Oils may seem so simple to someone who hasn't experience them or researched about oils. But actually Essential Oils are complex of various compounds. They are so complex of compounds, that it is nearly impossible to discover them completely. For an example, Citrus Essential Oil contains: 34 alcohols, 30 esters, 20 aldehydes, 14 ketones, 10 carboxylic acids, and 36 variety of terpenes. If you didn’t know, essential oils are lipid soluble portions of fluid that flows through the plant. They should only be extracted from certified organic or wild plants that are never exposed to fertilizers, herbicides or pesticides. There are two extracted methods for pure, therapeutic- grade essential oils; steam distillation and expression. Steam distillation is the common method for extracted oils, as 93% of oils are extracted by this method. This method is really hard to describe without a demonstration or photograph. So if you get a chance, type in “Steam Distillation for extracting essential oils,” on google images. You will get a relevant sense of how the process works. The Expression process is fairly easy to comprehend. This method is usually referred as the cold expression, or cold pressing. It is also used mainly on citrus fruits. You use mechanical pressure to press out the oils from the plant material, mainly from the peel or rind. After the oil is extracted, it is placed in a light- resistance bottle. The bottles are usually metal or dark glasses that provide 100% light blockage. The light- resistance bottle protects the oil from being broken down into the compounds, but eventually the essential won’t have the same effect as it would together. There are so many types of applications and oils itself. I’m still in the process of researching the applications, different essential oils, and the uses or reasoning for using different essential oils or oil blends