The clitoris is a small organ that is the girls' equivalent (in some ways) to a man's penis. The difference is that the penis has various uses, whereas the clitoris is there for no other reason save pleasure.
The visible part of the clitoris is about the size of a pea, but it does stretch back inside the body somewhat further. It is located at the bottom of the pubic bone, above the 'pee' hole (urethra) and above the opening to the vagina. It is partly enclosed by the folds of the labia - the 'lips' which surround your vagina.
All this will make much more sense if you look at your genitals in a mirror. It will be difficult to explain to future lovers - should you need to - exactly where your clitoris is if you don't know in detail yourself.
To find your clitoris, trace your inner labia forward to the place where they meet. Here you should see the tip, or the glans, of your clitoris protruding like a small pink bud from beneath its hood.
It is here that most of the direct pleasure during sex is to be had. When a woman becomes aroused the clitoris will fill with blood and its hood will retract. If you stimulate your clitoris during sex or masturbation, this will usually result in orgasm.
If your boyfriend or girlfriend falls silent, something's up.
Explain that you want to be 'let in' - then it can be good to give them space, tell them to call and let them come back to you