A biological process that follows orgasm. Semen is ejected from the penis during ejaculation. The primary biological purpose of ejaculation is impregnation, although the amount of sperm and semen in each ejaculation varies depending on a number of factors.

Many sexually transmitted infections (STIs) can be transmitted during (or prior to) ejaculation, and in order to avoid STIs and pregnancy, men can wear condoms to prevent direct contact with their partners. It is important to use condoms correctly and to withdraw immediately after ejaculation.