Vietnamese flag consists of a golden star with five points to represent farmers, workers, intellectuals, youth and soldiers. The red background pays tribute to the bloodshed during the wars. The flag of Vietnam, or “red flag with a gold star” (cờ đỏ sao vàng), was designed in 1940 and used during an uprising against French rule in southern Vietnam that year. The background was inspired by the red flag, used by the international communist movement since the Paris Commune of 1871.

Source: https://en.wikipedia.org/wiki/Flag_of_Vietnam