A condom is a sheath-shaped barrier device used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection (STIs). There are both male and female condoms.
With proper use—and use at every act of intercourse—women whose partners use male condoms experience a 2% per-year pregnancy rate. With typical use the rate of pregnancy is 18% per-year. Their use greatly decreases the risk of gonorrhea, chlamydia, trichomoniasis, hepatitis B, and HIV/AIDS. They also to a lesser extent protect against genital herpes, human papillomavirus (HPV), and syphilis.