The initiation of menstruation at puberty at the age between 9-15 years in human beings is called menarche. While around 50 years of age menstrual cycles ceases that i termed as menopause. Menarche is the stage that signifies the maturation and readiness of the female reproductive system for bearing child.
It signifies the capability of the ovaries to produce mature oocyte (female gamete) that can now be fertilised by the sperm and also that the uterus is capable of supporting the foetal growth and development.
Menopause signifies the end of child bearing age. At this age supply of healthy eggs is very low, the levels of the hormones secreted by the ovaries decline and the menstruation stops. The uterus no longer remains conductive for foetal growth.