How did stalin's view of communism differ from lenin and trotsky's?

 Best   After Lenin`s death in 1924, Joseph Stalin won a bitter power struggle against Trotsky. Trotsky advocated worldwide revolution, but Stalin`s aim to build socialism in one country appealed to Russian pride. Stalin created a ruthless totalitarian state. He pushed the country into rapid industrialization and forcibly collectivized agriculture at the expense of living standards. His ruthless `Russification ` program resulted in millions of Russians being deported to labor camps. Thousands of Soviet citizens died in his `blood purges of the 1930's. 
Trotsky`s policy of permanent revolution led to dismissal from the Politburo by Stalin in 1926 and eventual exile from Russia in 1929. He moved to Mexico in 1937 where he was assassinated in 1940. 
The theories of Communism advocated by Trotsky argued for the permanent worldwide revolution of the proletariat