Axis powers: It was an alliance led by Nazi Germany, Fascist Italy, and Japan. They all had dictatorial regimes.
German-Soviet Pact: The German-Soviet Pact or Ribbentrop-Molotov Pact was a non-aggression agreement signed by Nazi Germany and the Soviet Union one week before the WWII. It included a secret clause to invade Poland at the same time and to distribute Eastern Europe.
Blitzkrieg: The blitzkrieg was a new war tactic developed by Germany before the WWII and used since its beginning. It was based on the use of planes, the fast advance of tanks, and the occupation of the land by soldiers later. The troop advance was extremely fast and thanks to it, Germany occupied most of Europe between 1939-1941.
Battle of Britain
Battle of Britain: The Battle of Britain was the Nazi attempt to invade the UK between 1940 and 1941. Nazi Germany was defeated by the RAF (Royal Air Force).
Winston Churchill: Was the Prime Minister of the UK during the WWII. He was a British soldier, historian, politician, and Prime Minister. He led his country since 1940 after the Nazi conquest of France. He was appointed by the King Edward VIII in June 1940, after the conquest of France by Nazi Germany. The result was the victory of the UK. As a consequence, Hitler decided to break the German-Soviet Pact and to invade the Soviet Union in 1941.
Operation Barbarossa: Was the invasion of the Soviet Union by Nazi Germany in the summer of 1941.
Pearl Harbor: Japan attacked the American naval base in Pearl Harbor to sink most of the fleet the United States had in the Pacific Ocean. In the following months, Japan conquered many countries in Asia and set an Empire. (7th Dec. 1941) The following day, the President Franklin Roosevelt declared war on Japan and the USA entered the WWII.
Stalingrad: Because Germany needed oil to continue with the WWII and it was available in the oil fields of the Caucasus, but it was only possible to access it by conquering Stalingrad before. On the other hand, Hitler wants to conquer the city with the name of his main enemy as a psychological strike.
Holocaust: Holocaust or Shoah in Hebrew language is the murder of around 6 million Jews in Europe between 1941-1945. It specially affected Eastern Europe. It was organized by Nazi Germany but it was only possible with the participation of many collaborators from other countries.
Normandy landing: Was the arrival of the allies in western Europe at the end of the WWII. It was on the 6th Of June, 1944. The landing was carried out by soldiers from the USA, the UK, France, and Canada. It is usually said that this was an inflection point because without this military operation, Western Europe would be a territory with a Nazi regime as a communist regime. The Allies continued advancing to the east until they occupied Berlin in May 1945.