Aids is a disease caused by the human immunodeficiency virus (HIV), which kills or impairs cells of the immune system and progressively destroys the body. So the difference wo … uld be HIV is the disease which causes the symptom AIDS.HIV is the virus that causes AIDS.HIV doesnt necessarily turn into AIDS, but causes the immune system not to work as well. When a person's immune system is very severely affected they are diagnosed with AIDS. HIV itself never changed, just the immune function.ids is a disease caused by the human immunodeficiency virus (HIV), which kills or impairs cells of the immune system and progressively destroys the body. So the difference wo … uld be HIV is the disease which causes the symptom AIDS. HIV is the virus that causes AIDS.