The document discusses sexually transmitted infections (STIs), also known as sexually transmitted diseases (STDs). It provides information on the major STDs including HIV/AIDS, hepatitis, syphilis, chlamydia, gonorrhea, herpes, and human papillomavirus. It describes symptoms, modes of transmission, testing, and treatment for each STI. The document emphasizes that STDs remain a major public health issue, with millions of new cases occurring each year in the United States. Education and prevention are key to reducing the spread of STDs.