What is fire wall?

The Berlin Wall (German: Berliner Mauer or Antifaschistischer Schutzwall in the former German Democratic Republic), an iconic symbol of the Cold War, was initially constructed starting on August 13, 1961 and dismantled in the weeks following November 9, 1989. Part of the Iron Curtain, the Berlin Wall was the most prominent part of the GDR border system. Conceived by the East German administration of Walter Ulbricht and approved by Soviet leader Nikita Khrushchev the wall was a long separation barrier between West Berlin and East Germany (the German Democratic Republic), which closed the border between East and West Berlin for a period of 28 years. It was built during the post-World War II period of divided Germany, in an effort to stop the drain of labour and economic output associated with the daily migration of huge numbers of professionals and skilled workers from East to West Berlin, and the attendant defections, which had political and economic consequences for the Communist bloc. It effectively decreased emigration (escapes - "Republikflucht" in German) from 2.5 million between 1949 and 1962 to 5,000 between 1962 and 1989.