HIV, or Human Immunodeficiency Virus, is a virus that attacks the body's immune system, specifically the CD4 cells, which help fight infections. If left untreated, HIV can lead to AIDS (Acquired Immunodeficiency Syndrome), a condition where the immune system becomes severely weakened, making it difficult for the body to fight off infections and diseases. HIV is primarily spread through contact with infected bodily fluids, such as blood, semen, vaginal fluids, and breast milk. It can be transmitted through unprotected sex, sharing needles, or from mother to child during childbirth or breastfeeding. Early diagnosis and treatment with antiretroviral therapy can help manage the virus and allow individuals to live healthy lives.