Why was the  Battle of Stalingrad so important?

Context: The Battle of Stalingrad was a major battle on the Eastern Front of World War II where Nazi Germany and its allies unsuccessfully fought the Soviet Union for control of the city of Stalingrad in Southern Russia. The battle was marked by fierce close-quarters combat and direct assaults on civilians in air raids, with the battle epitomizing urban warfare.The Battle of Stalingrad was the deadliest battle to take place during the Second World War. Today, the Battle of Stalingrad is universally regarded as the turning point in the European Theatre of war, as it forced the Oberkommando der Wehrmacht to withdraw considerable military forces from other areas in occupied Europe to replace German losses on the Eastern Front, ending with the rout of the six field armies of Army Group B, including the destruction of Nazi Germany's 6th Army and an entire corps of its 4th Panzer Army. The victory at Stalingrad energized the Red Army and shifted the balance of power in the favour of the Soviets.

Answer: Battle of Stalingrad was critical and device fight between Nazi Germany and Soviet Union for few reasons. Firstly, it was deadliest and most intense fighting between two powers, binding very sizeable forces. The city itself was strategic as it hold the keys to the southern part and oil fields. Thirdly, it had a symbolic value for Stalin. And last but not least, it turned the tide in the war.