What is the difference between menstruation and menopause?

Menstruation is a monthly event of the uterus shedding it's lining. It begins at menarche (first period, usually about age 13) and continues until the onset of menopause (usually mid to late 40's). Menopause begins a change in the body where periods become at first, erratic, then infrequent, and finally stop all together. Past this point, the woman is considered no longer able to bear children.