The battle of Stalingrad was fought primarily between Germany and the Soviet Union, with the Soviet Union ultimately prevailing.
The battle was primarily fought with ground troops. The German Luftwaffe (air force) also conducted dozens of air strikes on the city of Stalingrad, but not the bulk of the battle was fought on the ground.
Germany had invaded the Soviet Union in what they called Operation Barbarossa, beginning in June, 1941. The Battle of Stalingrad, fought from August 1942 to February 1943, became the turning point in the war between German and Soviet forces on the Eastern front of World War II. Stalingrad was a protracted and extremely bloody military confrontation. More than 2 million troops were involved, and the death toll (including many thousands of Russian civilians) also numbered around two million. As reported by the History Channel, "The Battle of Stalingrad (one of Russia’s important industrial cities) ultimately turned the tide of World War II in favor of the Allied forces."