Soviet Russia's successful defence of their capital city Moscow against the onslaught of attacking German forces who sought to capture it in 1941 was a major turning point in the war. Hitler thus far had believed that if he could capture Moscow, the spirit of the Soviet army would be crushed and they would be at the Germans mercy. However, due to a combination of fierce and strategically executed Russian resistance along with reinforcements and the extreme cold of the Russian winter with temperatures down to as low as -22 degrees Celsius and colder, the Germans were never going to be able to capture Moscow. Losses were massive on both sides however. The Soviets suffered at least 650000 casualties while in just twenty days of fighting the German were believed to have lost as many as 150000 men. This was a mark of the devastation suffered in the Battle of Moscow.
https://www.youtube.com/watch?v=wSlBSOrKMVg ~ everything you need to know about the Battle of Moscow