I got this from another thread. Tracy pretty much sums it up.
http://www.longhaircareforum.com/showthread.php?t=48378&page=1&highlight=moisturizer
1) are some oils also moisturizers?
Technically, no. But sometimes when oil is added to a moisturizer the result is what we call "oil moisturizers"...not really technically possible - but it doesn't matter so much if u remember that oils coat and moisture penetrates. Only water can provide real moisture.
2) how can I tell the difference between oil and moisturizers?
True "moisturizers" are water based, which means water is usually the first ingredient. That's the best way to tell.
3) should water be the first ingrediant of a good moisturizer?
Yes.
4) what ingrediants do you think are important to look for an effective moisturizer?
Water...and maybe some oil if you don't want to add the two separately and don't mind using oil in the hair. Oil, either mixed into a pre-prepared water based formula, or added after a water based formula is applied, can help to seal in moisture as well as provide some lubrication and elasticity to the hair shaft.