How did the Normandy landings on June 6, 1944, open a second front in Europe?

The Normandy landings on June 6, 1944, established a critical second front in Western Europe by forcing Nazi Germany to divert military resources and attention away from the Eastern Front, where they were already under immense pressure from Soviet forces.123

By successfully landing U.S., British, and Canadian troops on five beachheads in France, the Allies created a permanent foothold in northwestern Europe. This operation, known as Operation Overlord, compelled the German high command to fight a two-front war, stretching their remaining military capacity to the breaking point. Following the liberation of northern France by the end of August 1944, Allied forces were able to reorganize for a direct drive into Germany, eventually meeting the advancing Red Army to bring about the collapse of the Nazi Reich.143