Berlin is the capital of Germany and its largest city by both area and population. It serves as one of the country's states, ranking as the third-smallest state in Germany by land area. The city is surrounded by the state of Brandenburg and borders its capital, Potsdam, to the southwest.
The city has a population of 3.7 million inhabitants within its limits, which is the highest population for any city in the European Union. The broader urban area of Berlin exceeds 5 million people, making it the most populous urban center in Germany. Additionally, the Berlin-Brandenburg capital region houses approximately 6 million residents and ranks as the fifth-largest metropolitan region in the European Union by GDP.