Final answer:
The labia majora are large folds of skin that run down from the mons on the vulva, protecting inner vulval structures, while the labia minora are smaller, serving to protect the urethral opening and reproductive tract entrance.
Step-by-step explanation:
The large folds of skin that run down the sides of the vulva from the mons are known as the labia majora. The purpose of the labia majora is to enclose and protect the inner structures of the vulva, including the labia minora, the entrance to the birth canal, and the urethra. These folds are covered with hair after puberty and are comprised of skin and fatty tissue, which offers a protective layer over the more sensitive areas within.
The labia minora, on the other hand, are thinner folds of skin located medially to the labia majora, and their purpose is to protect the urethral opening as well as the entrance to the reproductive tract.