Russian victory at Stalingrad was not only the turning point of the Second World War, but it was also one of the few major military triumphs of the Russian Army since the beginning of 20th Century up till 1943. Before 1943, the Russians had been humbled in the Russo-Japanese War (1904-05), and humiliated in World War 1 (1914-18).
However, the fortunes of Red Army took a turn in the right direction after the Germans were stopped dead in their tracks at the soon to be immortalised city of Stalingrad(now Volgograd).

Introduction
The battle of Stalingrad was fought from 23 August, 1942 to 2 February, 1943. The Siege of Stalingrad resulted in high levels of civilian and military casualties with most of the city reduced to rubble. General Paulus from Germany and General Zhukov from Russia were the most eminent commanders of this battle. 

German motive behind attacking Stalingrad
Stalingrad was an important city located on the Volga River. It guarded the way to Baku, and the oil rich region of Caucasus. The invading Germans believed that conquest of Stalingrad would be vital for their campaign further south, deep into Russian territory.The Russians were determined to defend it as it was a major industrial and transportation hub. Both Joseph Stalin and Adolf Hitler understood the symbolic importance of the only city to bear the Soviet dictator’s name. The fall of this city would have dealt a crushing blow to the morale of the Russian people.

A brief summary of the battle
The German assault on Stalingrad initiated with intense bombing campaign in late August; the Luftwaffe had a decisive advantage over the Russian air force. Much of the citiy’s industrial complex and infrastructure was destroyed in days.German ground forces launched their first attack on the city on September 13th. German forces paved their way to reach the banks of the river Volga and, by November, they were in possession of 90% of the city.
Soviets prepared for urban warfare by fortifying Stalingrad's buildings. Stalin did not allow civilians to leave the city as he believed the army would fight harder for a "living city." The city's factories continued to operate including one producing T-34 tanks. Soviet forces were determined to fight to the bitter end.
General Paulus’ best troops were tied down in a fierce urban combat with the Russians inside Stalingrad, leaving his flanks defended by Romanian, Hungarian and Italian troops. General Zhukov and General Vasilyevskiy, spotted this chunk in the armour of German war machine, and launched a counteroffensive named Operation Uranus on November 19, 1944. This strategy paid off and by November 23rd, over quarter of a million German troops had been encircled by the red army. Hitler had forbidden a strategic retreat. However, General Paulus realised that resistance was futile and hence he surrendered on February 2,1943.

Aftermath

"For Germany, the battle of Stalingrad was the biggest defeat in its history; for Russia, it became its greatest victory. Russia gained the right to be called a great European power near Poltava [in 1709], while Stalingrad was the beginning of its transformation into one of the two greatest world powers."(Hermann Doerr, German General, post-war memoirs)

Germany and her allies suffered a staggering number of approximately 750,000 casualties (killed, missing or wounded) and the Soviet losses stood around 478,741 killed or wounded, including another 650,000 wounded. The Soviets also captured over 90,000 Germans, most of whom perished before the war ended.
Germany couldn’t recover from the shock of Stalingrad, she had lost her best men and materials.
On the other hand, the morale of Allied forces received a much needed boost.
USSR capitalised on this victory and opened many new fronts against the axis in Eastern Europe.
Upon hearing of the disastrous defeat of Germans at the Battle of Stalingrad, Hitler rightly remarked,

"The God of War has gone over to the other side."

Conclusion
Today, the name of Stalingrad is synonymous with the unyielding resolve of urban defenders, all over the world, fighting against the military might of foreign oppressors. After the sacrifices of Stalingrad, the tide turned in favour of Allies and within a couple of years the Nazi Empire crumbled, Europe was free of Hitler’s tyranny. The name of Stalingrad will never fade from the annals of history; it will always be a symbol of hope for the underdogs.