Speaking in generalities, from a cook’s kitchen perspective …. The word oil doesn’t have to do with greasiness like is normally associated with the word oil. It has more to do with the essential oil’s poor solubility in water. Not mixing with water is a defining, shared characteristic between essential oils and the household items we call oils. You see in processing the plants for essential oils, the “residue” which is a result of the procedure include the oil and a water which is called a hydrosol or hydrolate (since you are new to this, when you get time maybe look at those. They are an often missed yet fabulous resource. This is the form I most use rose). For a visual maybe think about it like bone broth or gravy, the oil is basically “skimmed” off the top like you would fat from the soup of pan drippings. The volatile oil is on the top and the floral water on the bottom. What is interesting is that oil in cooking means bringing in a bit of fat to the recipe. Essential oils mix well with these fats although they are a volatile oil rather than fatty one, That is why oils like jojoba or coconut are often used as carriers and when those who recommend an internal method it is often best diluted in a fat first. And as you know, if you put olive oil in a pot of water boiling noodles – a little rises to the top and a wee bit will disperse. Same with soup and gravy, a bit of the fatty oil will still be part of the liquid, but rise to the top because it is still not water soluble. A true hydrolate has a wee bit of oil in it too. These are not perfect analogies but maybe it gives you something to which on can relate the information.