A condom is normally made of latex (rubber) and can be rolled onto the penis when it is stiff, before sexual intercourse. When the man has an orgasm the semen will be collected in the condom, preventing it getting into the woman’s genitals. Thus the condom stops the woman from getting pregnant. Because the condom covers the penis, stopping direct contact with the vagina, it also provides some protection against viral and bacterial infection. The chance of getting a sexually transmitted disease (STD) is much less if a condom is used, but areas not covered by the condom can still be infected. The best way to avoid infection is not to have sex with someone who might be infected with an STD.