Short answers, pulled from the story.
The Federal Republic of Germany (West Germany) was established on the 23rd of May 1949, and the German Democratic Republic (East Germany) was established on the 7th of October 1949. Both emerged from the four Allied occupation zones created after Germany's unconditional surrender on the 8th of May 1945.
The Berlin Wall was a barrier constructed in August 1961 by the East German government to stop the steady flow of East Germans migrating westward. By the end of the 1950s, thousands of younger East Germans were packing their bags and leaving, posing a growing problem for the GDR leadership.
The Wirtschaftswunder, or economic miracle, refers to the rapid economic recovery of West Germany between 1949 and 1960, during which the gross national product grew at an average annual rate of around 7 percent and unemployment fell from 10.3 percent to 1.2 percent. Key drivers included the currency reform of June 1948, which halted inflation by introducing the Deutsche Mark, Marshall Plan aid from 1948, and the worldwide demand for goods created by the Korean War of 1950-1953.
The Morgenthau Plan, proposed by Henry Morgenthau Jr., called for the pastoralization of Germany after the war, reducing it to an agricultural economy by destroying its industrial base. Although officially shelved, the plan influenced the punitive occupation directive JCS 1067 and the industrial level plans that capped German steel production at roughly 25 percent of prewar output. President Truman rescinded JCS 1067 in July 1947 on national security grounds.
Ostpolitik was Chancellor Willy Brandt's policy of rapprochement with West Germany's eastern neighbors, pursued from 1969. It produced the Moscow Agreement in August 1970, the Warsaw Agreement in December 1970, a four-power agreement over West Berlin in 1971, and an agreement on relations between West and East Germany in December 1972. During a visit to Warsaw on the 7th of December 1970, Brandt knelt before a monument to those killed in the Warsaw Ghetto Uprising in a gesture known as the Warschauer Kniefall.
Germany was reunited on the 3rd of October 1990, following the decline and fall of the Socialist Unity Party as East Germany's ruling party and the Peaceful Revolution there. The Treaty on the Final Settlement with Respect to Germany, concluded that year, formally resolved the territorial questions left open since 1945, with unified Germany confirming in treaties with Poland and the Soviet Union that the postwar territorial transfers had been permanent.