FO vs EO in a nutshell: educate me!

So I see a lot of soap artisans coming down on both sides of this, but the long and the short of it is that I know very little of scents and perfumes (and have an awful nose for picking things out anyway), so what are the real, practical differences between essential oils and fragrance oils when it comes to shave soap/cream? I know EO is more expensive, and that FO is "synthetic", but beyond that it sounds a lot to me like some sort of "all natural/organic" versus "science-ey stuff" debate that comes off as a little ridiculous (and borderline pretentious) in my local Whole Foods.

Can any experienced/knowledgable folks edify me on this one?