After the second world war, Vietnam was divided into two countries, North Vietnam and South Vietnam. This division lasted from 1954 to 1975. The main difference between the two countries were
1. North Vietnam was under communist rule while in South Vietnam Ngo Dinh Diem set up an oppressive authoritarian regime.His dictatorial regime was opposed by NLF.
2. The North was backed by the Soviet Union and China while the south was backed by the United States.
The two countries fought a long and bitter war in which the United States backed the south. The north emerged victorious in this war leading to the unification of the two countries into the present day Vietnam under communist rule.