The labia are the major externally visible portions of the vulva. In humans and other primates, there are two pairs of labia: the labia majora are large and thick folds of skin that cover the vulva's other parts while the labia minora are the inner folds of skin between the outer labia that surround and protect the urethral and vaginal openings.[1]
In other mammals, the labia majora are not present and the labia minora are instead referred to as the labia vulvae.[2][3][4]