HIV stands for Human Immunodeficiency Virus (HIV.) HIV is the virus that causes AIDS. Although HIV causes AIDS, a person can be infected with HIV for many years before AIDS develops.
AIDS stands for Acquired Immunodeficiency Syndrome. Acquired – means that the disease is not hereditary but develops after birth from contact with a disease-causing agent (in this case, HIV). Immunodeficiency – means that the disease is characterized by a weakening of the immune system. Syndrome – refers to a group of symptoms that collectively indicate or characterize a disease. In the case of AIDS this can include the development of certain infections and/or cancers, as well as a decrease in the number of certain cells in a person’s immune system.
A diagnosis of HIV/AIDS is made by using specific clinical or laboratory standards.
Centers for Disease Control Definition