It is the fully matured follicle, which ruptures and discharges the ovum at the time of the ovulatory phase.
The ovulatory phase or ovulation refers to the time when the egg is discharged from the dominant follicle within an ovary.
The ovary is the pair of female glands, which are the part of the female reproductive system, in which the formation of eggs takes place and the female hormones progesterone and estrogen are made.
The egg is discharged into the fallopian tube, where it can get fertilized by the sperm.
Post ovulation, the Graafian follicle, converts into the corpus luteum that secretes progesterone, which plays an essential role in the maintenance of pregnancy.