Condoms are made of solid rubber. Sperm and germs cannot pass through so condoms give good protection from pregnancy, HIV/AIDS and other Sexually Transmitted Infections (STIs). Condoms only work if used correctly-put one on as soon as you think you will have sex because fluids released before ejaculation can contain sperm and some infections that can be passed by skin to skin contact.
Attribution: Straight Talk Foundation & Marie Stopes