Answer:
After World War 2, Germany was split in half by the occupying forces. You had the Western Allies (USA, UK and France) occupy West Germany while the Soviet Union occupied East Germany. Tensions between the USA and the Soviet Union, West and East, Capitalism and Communism, etc, etc, led to these two occupied zones becoming more independent from one another until they split. East Germany became known as the German Democratic Republic (GDR) while West Germany became known as the Federal Republic of Germany.
The two Germany's reunified after the collapse of the Soviet Union and Communism in 1990