The term "Stalinism" was used by anti-Soviet Marxists, particularly Trotskyists, to distinguish the policies of the Soviet Union from those they regard as more true to Marxism. Trotskyists argue that Stalinism is not socialism, but rather a form of "state capitalism;" that is, a system in which exploitation is merely controlled by the state. The term is also used by more democratic Marxists (as well as many non-Marxists) to condemn the totalitarian variety of Communism that still exists in states such as North Korea.
Building on Lenin's work, Stalin expanded the centralized bureaucratic system of the Soviet Union during the 1930s. A series of two five-year plans led to a massive expansion of the Soviet economy. Large increases were seen in many sectors, especially coal and iron production. Society was brought from a position decades behind the West to one of near economic and scientific equality within thirty years. Some economic historians now believe it to be the fastest economic growth ever achieved.
After Stalin's death in 1953, Stalin's successor Nikita Khrushchev repudiated his policies and condemned Stalinism. Only after that both the people of the USSR and the rest of the world have slowly become aware what really happened during Stalin' rule. See Gulag and History of the Soviet Union: Part I articles.
Many parallels can be seen between Stalinism and the economic policy of Czar Peter the Great. Both men desperately wanted Russia to catch up to the western European states. Both succeeded to an extent, turning Russia temporarily into Europe's leading power. In both cases it only took a few decades for the forced economic growth to evaporate, and for Russia to once more become one of the poorest nations in Europe.