I think it was in response to where to buy and what to use them for, I can answer.
You can buy them at health food stores and through various companies like young living and doterra via a consultant. There is even a new company called spark naturals you can order online. Or you can get your own account and order at discount like some of us o.
I used to buy mine via Camden grey website and used for soap making ,but now I also use them medicinally so I signed up for a wholesale account with doterra and I order them online.
The reason I picked doterra is simply that a friend told me about them I tried and loved them. I have friends who use young living and love them too.
As for what you can do with them, almost anything.
They are not meant to cure any disease, but what they do is strengthen immunity and allow your body to work with itself to heal.
Here is a feat reference site, you can look up health concerns and see what oils help or you can look up oils and see what they can do.
It has a doterra slant, but it does state it applies to other essential oils as well.
http://www.everythingessential.me/