Condoms are the only contraceptive that also provide the users with protection from sexually transmitted infections (STI). It is sensible for someone to use a condom if they have sex with a person who they are not certain does not have any infections. Often people are themselves unaware of whether they have an STI.
This map shows the distribution of young women who did use a condom last time they had ‘high-risk’ sex. That is sex with someone they are not married to or do not live with. Not everyone has access to condoms, can demand their use, or wants to use them. Only 40% of young women around the world used condoms the last time they had risky sex.