This is a very solid foundation primer. It smooths over your skin, making pores and little lines much less noticeable and giving your skin an awesomely soft feel. It doesn't clog pores, smell gross, or feel heavy. A little goes a long way, and ultimately you'll look much better with this on under your foundation.
That said, Monistat's Anti-Chafing Gel, which you can get at the drugstore for ~$6, is the same thing. Literally the same thing.