a clitoral orgasm is what you experience by rubbing your clit. a vaginal (or G-spot) orgasm is brought about internally.
there are vast differences in people's accounts of the "feeling". oftentimes the vaginal orgasm will be accompanied by a "squirting" or ejaculation of fluid, while the clitoral orgasm is accompanied by vaginal "wetness", but no squirting.
personally, 90% of my orgasms are clitoral...and i enjoy them immensely. 10% are vaginal (g-spot) and they are pretty earth shattering as well, but in a very different way.
hope this info helps. let me know if you need further detail.
jasmine