Everything you can see below is called a vulva. ie pretty much everything you can feel or see with a little mirror 70s style is called a vulva. Unless you're super flexible. Or have long fingers. But let's not go there ;)
2. Labia majora
5. Hood of the clitoris (also called prepuce)
6. Labia minora
7. Urethral orifice - or urethral opening (where you pee out of)
8. Opening of the vagina
As far as you can see in this picture the vagina is a small hole. Now for those of us who have birthed children via one they may not look quite so tidy, but I promise you as someone who has seen quite a lot of them now that they are not a major part of the genitalia. Sure they're fun and you can do fun things with them, but if the only area of your vulva that gets any action is your vagina then you're certainly missing out. Aside from anything else did you know that the portion of the vagina not considered part of the vulva has no sensation?
This is something that cheeses me off considerably. People who reduce the female external genitalia to a vagina piss me off. If you do it, you piss me off. Just letting you know. It is NOT a "correct" term. I don't care if your Aunty, Sister, Mum and 4 ladies from Mothers Group call it a vagina. It STILL ISN'T CORRECT. Don't give me shit that it's too hard to teach them the "correct" terms. VULVA is easier to say. VULVA has less letters. VULVA ACTUALLY IS CORRECT.
I use tummy and belly also. I don't teach my children correct anatomical names and am happy with accepted euphemisms. But VAGINA is not a euphemism. It is its own special anatomical zone. It does its own awesome things. But it is not and never will be a vulva. Unless you need reconstructive surgery. And TRUST me, you dn't want that.