HIV (human immunodeficiency virus) is the virus that can lead to AIDS (acquired immunodeficiency syndrome). The human body CANNOT get rid of HIV. Once you have HIV, you have it for life. Anyone who is sexually active can get HIV.
HIV is spread by contact with the bodily fluids of an infected person. In the U.S., some of the ways HIV is spread include having sex with or sharing drug injection equipment with an HIV-infected person (source). HIV can also be passed from mother to child during pregnancy, birth, or breastfeeding.