Who: The Vietnam War was a Cold War era war that involved the Vietnam and the United States. It also involved several communist and anti- communist countries.
What: The Vietnam war was a war the involved communist and anti- communist forces. The communist North Vietnam and the the Republic of South Vietnam. The USA got involved in the fighting with South Vietnam while the Soviet Union and their allies helped North Vietnam.
Where: The war took place in the countries of North Vietnam, South Vietnam, Cambodia and Laos .
When: The War took place from December 1956 to April 1975 ( 18 years,4 months, 4 weeks and 1 day).
Why: The war was taking place as part of the war of communism.