how was the Berlin Wall a symbol for a world divided between the two camps of nato and the Warsaw Pact

The Berlin Wall divided Berlin in two parts: East Berlin and West Berlin. The former was the capital of the communist German Democratic Republic, and the latter was a western, democratic enclave born from the occupation zones of the Western Allies after WWII.

Berlin was a symbol of the division of Europe and the confrontation between capitalism and Western democracy on one side, and communism, on the other side. Both parts of the city were sort of showrooms for their systems. American troops were stationed in the western part, and Soviet troops were stationed on the eastern part. The wall ran along the boundaries of the former Soviet zone with the western occupation zones. So, here NATO and Warsaw Pact forces stood side by side. For all these reasons, it's said the Berlin Wall was a symbol of a Cold War world divided in two camps.