AIDS- Acquired Immune Deficiency Syndrome.
It is a disease which is acquired by having unprotected sex.
It cannot be recognized as its symptoms are not visible for years.
It is also known as HIV.
It is spread due to the contaminated blood transfusions,unsterilized needles,from mother to child,etc.
HIV virus can live in the body fluids like blood,serum,breast milk,tears,etc.
There is no prevention for this disease.
Without treatment a person can live until 9 to 11 years.
You can more information from other sources.
hope you understood