An ovary is a small gland and an essential part of a woman's reproductive system. The female reproductive system includes two ovaries, one on each side of the pelvic area. Contrary to popular belief, the ovaries don't take turns from month to month. They both develop follicles with potential eggs, and the "best egg" wins. You can read more about ovulation here.
At birth, a woman's ovary contains every potential egg it will ever have. (As opposed to men, whose reproductive system includes the making of new sperm cells throughout their life.) While women are born with millions of eggs, at puberty only 300,000 potential eggs are left. This number continues to decline with age. You can read more about age and fertility here.
Besides the housing and development of eggs, the ovaries also secrete important hormones, including estrogen, progesterone and small amounts of testosterone.
