D-Day, commemorated on June 6, 1944, refers to the Allied invasion of Normandy during World War II. This military operation, known as Operation Overlord, marked a crucial turning point in the war against Nazi Germany. Over 156,000 Allied troops, from the United States, United Kingdom, Canada, and other nations, landed on five beachheads along the French coastline. The successful invasion established a vital foothold in Europe, leading to the liberation of Western Europe from Nazi control. D-Day remains a significant date in history, symbolizing courage, sacrifice, and the fight against tyranny.