What is the 'smell' or 'scent' of a woman's vagina and why is it considered a factor in erotic attraction ?

We all know about Gwyneth's candle but I'm betting without having much experience (and none in recent years) to back up my view that it's all bullshit.

It's been so long that I really don't know or remember what the 'smell' or 'scent' of a woman's vagina is like (or supposed to be like) or even really what to do with one. Also why and how is it meant to be automatically erotically attractive and 'desirable'?