Difference between HIV and AIDS

Human Immunodeficiency Virus:
It is a virus that causes an infection. This infection can be symptomatic or asymptomatic. Being HIV positive does not mean being sick.
Acquired Immunodeficiency Syndrome:
It represents the final advanced stage of HIV infection if left untreated. This stage is marked by a decline in immune cells (CD4+ < 200 /mm³) and the occurrence of opportunistic infections.