Sexually Transmitted Infection (STI) is a term used to describe infections that are primarily spread through sexual contact, including vaginal, anal, and oral sex. The term STI is often preferred over the older "sexually transmitted disease" (STD) because a person may have an infection without displaying any symptoms of disease, as noted by organizations like the CDC. These infections are caused by various bacteria, viruses, and parasites. Common examples of STIs include Chlamydia, Gonorrhea, Syphilis, Human Papillomavirus (HPV), Herpes, and Human Immunodeficiency Virus (HIV). Many STIs can be treated or cured, particularly those caused by bacteria and parasites, while viral infections like herpes and HIV can be managed with antiviral medication to reduce symptoms and transmission risk. Routine screening is crucial for individuals who are sexually active, as many infections are asymptomatic and can lead to serious health complications, such as infertility or certain cancers, if left untreated.