HIV     =   Human Immunodeficiency Virus

 AIDS  =    Acquired Immunodeficiency Syndrome

The Human Immunodeficiency Virus is the virus that causes AIDS.  The virus might be passed from one person to another when infected blood, semen, or vaginal secretions come in contact with an uninfected person's broken skin or mucous membranes.  In addition, infected pregnant woman cab pass HIV to their baby during pregnancy or delivery, as well as through breast-feeding.  People with HIV have what is called HIV infection.  Some of these people will develop AIDS as an resultof their HIV infection

AIDS - Acquires Immunodeficiency Syndrome means :  

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 in the immune system 

Syndrome - means a group of symptoms that together indicate a disease.  When it comes to AIDSthis will include the development of certain infections and/or cancers, as well as a decrease in the number of certain celles in the human immune system.