This has been long debated.
The moisture and oil thing depends on who you ask and is really a matter of semantics if you ask me.
Though oil softens, nourishes, adds shine, etc-- Oil is not a "moisturizer." Moisturization, or hydration, is a property of water. But oil is very important as a support for hydration.
Oil can
support the moisturization of the hair fiber by 1.) sealing moisture into the shaft and 2.) in some special cases- with oils that have protein affinity like coconut oil, by supporting the protein structure of the hair fiber. Coconut oil in particular has been found to prevent protein loss. This helps with moisturization b/c intact proteins reduce the hair's porosity. Coconut oil is one of those rare oils that can bind to protein, but it does not itself impart any sort of hydration to the hair fiber- penetrating or not. All oils are hydrophobic-- meaning they work by repelling water at the end of the day. Coconut's ability to hold onto those proteins and repel water at the same time makes it really, really useful for preventing natural washing stress to the hair fiber.
And its my favorite oil if you can't tell so I could go on and on about the benefits of this stuff.
S-Curl, Care Free Cure are moisturizing products. But if I'm not mistaken they tend to be cone-heavy, and cones can act like shaft-coating oils. So too much of them can work against you if you don't clarify regularly.
Hydrated hair has a natural sheen to it. It also has a nice, weight to it. It is strong, yet soft-- and is relatively free from breakage. It's different from artificial shine which tends to be a temporary high gloss, coated kind of feel that wears off. The best moisturization/hydration
hands down comes from regular deep conditioning w/ a balance of protein and moisture. There isn't a moisturizing product or oil product on the planet that can replace this in my opinion!