Marx developed many of the ideas that eventually became Russian Communism, but Lenin was the one to implement those ideas. Both leaders believed that workers should control their own fate instead of relying on the rich and powerful.
Marx believed that revolutions would take place spontaneously in advanced, industrialized states. Instead, the revolution he started took place in Russia.
Since Russia was populated mostly by peasant farmers, Lenin focused on industrial development. He believed that capitalist countries avoided revolution by forming new colonies and bringing enough wealth home to keep the population happy. Lenin also believed that an organized political party led by wealthier, more educated people is needed to form a revolution. These people were called bourgeoisie. Lenin formed a dictatorship that Marx probably would have been opposed to. Marx wanted all people to have the same wealth and opportunities.