According to orthodox Marxism, it was necessary for the conditions of capitalism to ripen before a socialist revolution could take place. This meant that such revolutions could only break out in advanced industrialized societies. Yet the Russian Revolution of October 1917 appeared to turn received wisdom on its head as Russia's was an overwhelmingly agrarian economy, with the vast majority of its people working the land.
Having achieved power, the Bolsheviks were determined to do everything they could to hold on to it. Among other things, this involved embarking upon a rapid program of industrialization, creating millions of workers on which the future stability and survival of the new regime would depend. The Bolsheviks were inherently distrustful of the peasantry for their conservatism and wanted instead to construct a true workers' state on the basis of a new, mass-industrialized society, hence the overriding necessity of industrialization.
This process was greatly accelerated under Stalin, who set (over)ambitious plans for catching up with the advanced capitalist powers of the West. Ever more demanding output and production targets became the order of the day. But without proper planning and adequate supplies, huge problems soon developed. As well as its chronic inefficiency, Stalin's industrialization plan caused suffering on a massive scale, with those toiling in the new factories slaving away under appalling conditions in this so-called workers' paradise.
As for the peasants, they were forced into collective farms controlled by the government. They were required to produce food which would mainly be used to supply the workers in the rapidly expanding industrial towns and cities. Once again, however, lack of proper foresight and planning led to disaster. Agricultural output tanked, leading to famine on a catastrophic scale. To make matters worse, the regime actually confiscated already dwindling stocks of grain to sell abroad in order to fund the purchase of industrial tools and machinery. The consequences were truly horrific, with tens of millions of people dying of starvation. As well as the immense suffering they caused, mass industrialization and collectivization fundamentally changed the whole nature of Soviet society, as they were intended to do.