HIV (Human Immunodeficiency Virus) is a virus that attacks and breaks down the body's immune system – our "internal defense force" that fights off infections and disease. When the immune system becomes weak, we lose our protection against illness and can develop serious, often life-threatening, infections and cancers.
H - Human - because this virus can only infect human beings.
I - Immuno-deficiency - because the effect of the virus creates a deficiency; a failure to work properly, within the body's immune
V - Virus - because this organism is a virus; which means that it is incapable of reproducing by itself. It reproduces by taking over
the machinery of the human cell.