When you see a girl naked you see the mons and the outer lips (labia majora). The outer lips are the two folds of spongy flesh that extend from the mons and are covered with hair. They enclose the inner lips (labia minora).
When you open the outer lips, the inner lips become visible. These are soft as rose petals and hairless. They vary quite a bit in appearance from girl to girl.
The inner lips are very sensitive to touch. If you want to get sexually aroused don’t only caress your clitoris, but also spend time on your inner lips.
When you open the inner lips you’ll see the clitoris, urethral opening and vaginal entrance.

Great diversity from girl to girl
What happens to the inner and outer lips when a girl gets excited?

“My labia minora are larger than my labia majora. Is that normal? I’m afraid my boyfriend will find this ugly if he sees me naked.”
“My inner lips hurt when I wear tight pants. Can I do anything about this?"
“I have little bumps on my labia minora and majora. Should I worry about this?”