This is the 527th most frequent German word.
hauptstadt
Capital city.
Here, 'Hauptstadt' is used in its most common usage to denote a capital city, specifically Berlin being the capital of Germany.
Berlin ist die Hauptstadt von Deutschland.
Berlin is the capital of Germany.
In this sentence, 'Hauptstadt' is used generically to refer to any capital city, representing a general concept.
Die Hauptstadt eines Landes hat oft eine große wirtschaftliche Bedeutung.
The capital city of a country often has significant economic importance.
The plural form 'Hauptstädte' is used here to talk about capitals of many countries, demonstrating the word's adaptability to pluralization.