Safe sex is sexual activity engaged in by people who have taken precautions to protect themselves against sexually transmitted infections (STIs) such as HIV.[1] It is also referred to as safer sex or protected sex, while unsafe or unprotected sex is sexual activity engaged in without precautions, especially forgoing condom use.

Some sources prefer the term safer sex to more precisely reflect the fact that these practices reduce, but do not always completely eliminate, the risk of disease transmission. The term sexually transmitted infections (STIs) has gradually become preferred over sexually transmitted diseases (STDs) among medical sources, as it has a broader range of meaning; a person may be infected, and may potentially infect others, without showing signs of disease.[2]