The mons pubis (Latin for "pubic mound"), also known as the mons veneris (Latin, mound of Venus) or simply the mons, is the fatty tissue lying above the pubic bone of adult women, anterior to the symphysis pubis. The mons pubis forms the anterior portion of the vulva.
The size of the mons pubis varies with the general level of hormone and body fat. After puberty it is covered with pubic hair and enlarges. In human females this mound is made of fat and is supposed to be larger. It provides protection of the pubic bone during intercourse.
The mons pubis divides into the labia majora (literally "larger lips") on either side of the furrow, known as the cleft of venus, that surrounds the labia minora, clitoris, vaginal opening, and other structures of the vulval vestibule. The fatty tissue of the mons veneris is sensitive to estrogen, causing a distinct mound to form with the onset of puberty. This pushes the forward portion of the labia majora out and away from the pubic bone.
abridged version derived from: http://www.wikipedia.org