This document discusses sexually transmitted infections (STIs), HIV, and AIDS. It defines them as diseases that can be transmitted through unprotected sex. HIV attacks and weakens the immune system by destroying CD4 cells. If untreated, this leads to AIDS, where opportunistic infections take advantage of the weakened system. While there is no cure for HIV/AIDS, antiretroviral therapy can suppress the virus and prevent development of AIDS, allowing those infected to live long and healthy lives if they adhere to the daily medication regimen. The document emphasizes that not all those with HIV will develop AIDS, and one cannot acquire AIDS without first being infected by HIV.