Ovulation is the time in the menstrual or fertility cycle when the egg or ovum is released from the ovary, travels down the fallopian tube and enters the uterus to await possible fertilization. Ovulation occurs about halfway through the menstrual cycle and the days surrounding it are considering the most likely time for conception to occur.
More About Ovulation
Another part of ovulation is the thickening of the uterine lining which happens in preparation for the egg's arrival. If the egg does not become fertilized, the lining is then shed. This results in what we know as menstruation.
Many couples use diligent tracking of ovulation to assist when they are trying to conceive. Couples who use the "rhythm method" or "fertility awareness" as their birth control also pay close attention to the female partner's ovulation.