The female orgasm is an elusive and mysterious thing.

Achieving an orgasm at all can be challenging for some women, while others have them while exercising in the gym. There is no set mould or pattern - but one thing that studies HAVE confirmed, is that there are two different types of orgasm - clitoral and vaginal. Distinguishing between the two is quite simple - a clitoral orgasm is achieved through stimulating the clitoris, and can be achieved with no penetration of the vagina at all. On the other hand, a vaginal orgasm is achieved through penetration and is generally associated with a much deeper, satisfying orgasm. However, it gets tricky as most women need external stimulation as well as penetration to achieve a vaginal orgasm, meaning that it can be hard to tell which type of orgasm you have had. Differences between the two have been heavily debated and are a source of controversy. A study conducted by French gynaecologists Odile Buisson and Emmanuele A Jannini revealed that external clitoral stimulation did not involve the internal root of the clitoris, but, vaginal stimulation involved both the root and the external clitoris. This in turn affects the blood flow and leads to differing sensations. The only way to be sure you've reached vaginal orgasm, is to skip the external stimulation altogether and attempt to orgasm by penetration alone. According to a study in The Journal of Sexual Medicine, achieving vaginal orgasm is more likely the longer the sex lasts. All in all it is a pretty confusing topic - but in a way that's comforting as there's no real "right or wrong". We'll just have to do some investigative journalism to find out.