This document discusses sexually transmitted diseases (STDs), including how they are contracted through sexual contact or other means like childbirth. It then lists and categorizes common STDs such as chlamydia, gonorrhea, herpes, and HIV. The document outlines the viruses, bacteria, and parasites that cause STDs and their risk factors like unprotected sex or multiple partners. Finally, it discusses preventive measures like safe sex practices and treatments using antibiotics or antiviral drugs.