In 1961, the East German government built the Berlin wall, dividing Berlin into two halves. They did this to stop the flow of Germans from East Germany to West Germany, because at this time Germany was divided into two separate countries. Germany had been divided after World War II to keep it weak and prevent another war. East Germans were leaving in great numbers because the west provided more freedom and a better standard of living. (Berlin was surrounded at the time by East Germany, a Soviet-controlled state, with West Berlin being the one small area of the city that was part of West Germany).
The wall was bad publicity for East Germany, as it suggested that the only way to keep people inside its territory was to seal them in with a machine-gun guarded wall. While the wall did help stabilize the East Berlin economy, it also cut some East Germans off from their jobs in West Berlin as well from consumer goods available in the west. It had the effect in East Berlin of pulling those Germans more firmly into the Soviet orbit. East Berlin was a poorer city than West Berlin, and did not, for instance, modernize its infrastructure as West Berlin did. If you go to Berlin today, you can tell where East Berlin once ended: that side of the city still uses old-fashioned tram cars that were long ago replaced in the western side of the city. West Berliners were actually made less nervous that the Soviets would try to take over the entire city after the wall went up. West Berliners, of course, did not suffer from the loss of consumer goods the way East Berliners did, but on both sides, family members were cut off from each other.
The Berlin Wall had a much greater impact on the East than it did on the West, but it still affected West Berlin.
The most important impact of the Wall on East Berlin was that it caged the people, curtailing their freedom. The presence of the Wall made it so that people of the East could not escape from their repressive society and reach freedom in the West.
For West Berlin, the impact of the Wall was more positive. On the bad side, it did prevent many from seeing relatives in the East. However, the presence of the Wall made Berlin much more relevant that it otherwise would have been. It made West Berlin a symbol of freedom for the whole Western world. That is, for example, why Pres. Kennedy came to Berlin and gave his speech saying that he was a Berliner.
So, the building of the Berlin Wall was much more negative for people in East Berlin than it was for those in West Berlin.