Those two were. I'll give you an overview of both - you can ask me whatever comes to mind.
Cuba
The Cuban Revolution was the armed overthrow of
Fulgencio Batista by groups of guerrillas. It was the result of corruption, rampant crime, poverty and foreign business exploitation. When successful,
Fidel Castro was installed as president, immediately passing Agrarian Reform, which gave ownership to agricultural property to workers and the state. He also embarked on a literacy campaign, giving free education (on all levels) to all citizens. Medicine and housing were also provided, free of cost. Living standards have greatly improved as a result of these measure. Of a revolutionary sentiment, Castro has decried the United States' for passing a trade embargo, and crippling the Cuban economy. But with the help of other Latin American socialisms, and by keeping those disloyal to the cause out of government - by vetting the candidacy of individuals running for the roughly 50% of government positions open for elections -, the government has managed to stave off disaster.
Democracy has been a problem, along with political persecution, but many Cubans recognize that to maintain socialism in the face of immense capitalist pressure, these things are necessary. It's a kind of siege mentality that likely won't disappear unless a strong international bloc is formed.
Russia
Russia is a lot more complex. So you'll probably need to be asking a lot more questions. Especially since I'm writing a post, not a book.
The Revolution was started with the overthrow of
Tsar Nicholas II by a popular uprising, and the subsequent overthrow of a socialist-majority republic by the
Bolshevik Party. Soviets, industrial communities led by workers' councils, were intended to elect representatives to lead the country, but upon realizing this was impossible - due to the lack of a democratic tradition, and the decision to industrialize the country through a Marxist programme -,
V. I. Lenin transferred power to a dictator. The New Economic Policy is the most crucial thing to understand about the Russian Revolution. See, in the fist stage, a mixed-economy was established, with an immense tax on peasant surpluses being used to fund industrial development. After the end of Lenin's years, debates over a second stage began.
Leon Trotsky and
Yevgeni Preobrazhensky formed the left faction, advocating more rapid development (using a larger peasant tax) to ward off capitalist elements forming within the country. And
Nikolai Bukharin and
Joseph Stalin formed the center-right faction, advocating slower development by largely following the first stage's path. But ultimately, neither won out, with Stalin using political dealings to gain power and implement "socialism from above", which consisted of mass political repression, unreasonable taxes and quotas for peasants (leading to a famine), and cooperation with US enterprises.
The economy is today more capitalist than it's ever been, due to opposition to the brutality of the Stalin years.
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That was grossly summarized, but it'll suffice.