Indochina, which has been referred to in the past as French Indochina, is a region of Southeast Asia made up of Vietnam, Laos and Cambodia. The reason why this term is applied to this group of countries is because they were formally associated with French rule and have various influences from the surrounding Chinese and Indian regions.
Indochina had been under French rule for much time up until the middle of the 20th century, when the end of a Japanese occupation led Vietnam to establish itself under Ho Chi Minh as its own central authority. This would soon lead to conflicts with the French, referred to as the First Indochina War. Treaties soon ratified the three regions as their own independent countries, now known as Vietnam, Laos and Cambodia. But these nations were being ruled by puppet governments set by the French, and it wasn't until the Geneva Conference of 1954 that this was amended.
In 2014, the nations that make up Indochina are diverse. They are mainly agricultural nations and have significant poverty, but they are also urbanizing and filled with their own rich cultures.
Indochina must not be confused with Cochinchina, which is the name of the southernmost region of Vietnam that was an occupied colony. It would eventually be ceded to France by 1862, becoming one of France's overseas territories until 1949 when it was merged officially with Vietnam.