2. What is the Berlin Wall? Where is it? How was it formed? And more..?

The Berlin Wall was a wall through the city of Berlin, dividing the Communist controlled East Berlin from the democratically controlled West Berlin. 

At the end of WWII, the four Allied powers (US, UK, USSR, and France) divided up Germany into zones of occupation.  They also divided the German capital of Berlin into similar zones.  Initially this was intended to be temporary, until the Allies could stand up a non-Nazi German government to control things.  But it ended up becoming permanent when the Soviets wanted to retain effective control of their zone.  So the large Soviet zone became East Germany, a communist puppet government allied with the Soviets.  The three other zones were merged into West Germany.  Berlin was in the middle of the Soviet zone but was divided between the Soviets and the western allies.  Initially, the Soviets tried to forced the West to hand over their parts of Berlin by blockading the city.  But the West responded with the Berlin Airlift where they flew supplies into the western part of the city (the Soviets were unwilling to risk a war with the US and so declined to simply shoot down the planes).  So a permanent situation evolved where Berlin, which was located in East Germany, was divided into East Berlin and West Berlin.  East Berlin remained the capital of the new East Germany while the West German capital was moved to the city of Bonn for security reasons.  West Berlin, as an island of democracy in the middle of a totalitarian communist state, became an iconic symbol during the Cold War. 

But West Berlin posed a security problem for the East Germans and their Soviet masters.  Initially there was no physical divison between the halves of the city.  The streets were unmonitored, the subway still ran across the entire city, people still circulated freely.  But as the East German government became more oppressive, East Germans began fleeing the west.  And in Berlin that was really really easy.  You could just walk to the other side of the city on ask fro asylum.  It became a rel security concern.  So the East Germans began militarizing the border more.  They shut down subway access to the West (just by having the trains not stop there) they put up checkpoints on the streets, they bricked up buildings with cross border access.  But this wasn't enough.  By the early 1960s they began constructing a wall.  it would encircle West Berlin and keep people from escaping.  The Wall was a large concrete barrier topped with razor wire and featuring guard towers.  The East Berlin side of the wall had a cleared free fire zone where  people entering could be shot.  Movement to West Berlin was controlled through a few authorized points of entry.  This dramatically cut down on escapes.  But it also gave the West a potent symbol.  The Berlin Wall became a symbol of Communist oppression and authoritarianism.  A few years after its construction, US President John Kennedy visited Berlin and declared that "Ich bin ein Berliner" (I am a Berliner).  Twenty years later, President Reagan demanded that Soviet leader Mikhail Gorbachev "tear down this wall".  In 1989, the East German government fell in a bloodless uprising, part of a series of uprisings which dismantled all the Communist regimes of Eastern Europe (except for the Soviet Union itself which hung on for a few more years).  One of the first things that East Berliners did, and one of the most inconic, was to cross into the western part of the city.  That very night, they began tearing down parts of the Berlin Wall with hand tools and whatever else they could find.  With Germany reunified, Berlin is once again the capital city, a unified city.  The Wall only exists in a few fragments left for historical purposes in Berlin, and in chunks which were sent to historical institutions in Germany and abroad.

The Berlin Wall was a dead zone people barrier put up by the communist Russian Soviet Union to prevent people of Soviet East Berlin and Soviet Empire from leaving, as no one wanted to live in the Soviet Empire (except those running it), it was built to keep the population of the Soviet Empire locked in.

It was in Berlin Germany dividing the city. It was there 1961-1991. It also went all around the border of Soviet East Germany to keep people locked in to serve the Soviet state/ communism.

It consisted of a concrete wall 20' high/ 10' wide with watchtowers on top + barbed wire, electrified wire, land mine zone and killing field for machine guns all out to 1000' in front of the concrete.

Many people tried to cross the 'Wall' to escape the Soviets, few made it, about 10,000 were killed trying/ another 20,000 caught and tortured.

The fall of the Wall and it's breaking up in 1991 marked the end of Soviet and world communism.   

oi..a lot of information...but put it simply east side vs west side..it was in Berlin