Marxism-Leninism is a political ideology that emerged in the 20th century, and is based on the ideas of Karl Marx and Vladimir Lenin. It is a form of socialism that emphasizes the need for a vanguard party to lead the working class in a revolution to overthrow capitalism, and the establishment of a socialist state to guide the transition to communism.

Marxism-Leninism is rooted in Marxist theory, which sees history as a struggle between classes. According to Marx, the working class is exploited by the capitalist class, and this exploitation leads to alienation and suffering. Marx believed that the only way to end this exploitation was for the working class to unite and overthrow the capitalist class, and establish a socialist state that would lead to the eventual transition to communism.

Lenin built on Marx's ideas, and argued that a vanguard party was necessary to lead the working class in the revolution. Lenin believed that the working class was not capable of achieving revolution on its own, and that a disciplined and centralized party was needed to guide the struggle. This party would be made up of the most class-conscious and committed members of the working class, and would use various tactics to mobilize the masses and overthrow the ruling class.

Once the socialist state was established, according to Marxism-Leninism, it would guide the transition to communism by implementing policies that would gradually eliminate the remnants of capitalism and move towards a fully socialist economy. This would involve the nationalization of key industries, the abolition of private property, and the establishment of a planned economy that would be directed by the state.

Critics of Marxism-Leninism argue that it leads to authoritarianism and the concentration of power in the hands of the party elite. They argue that the emphasis on a vanguard party leads to a dictatorship of the proletariat, in which the party makes decisions on behalf of the people, rather than the people themselves having democratic control over the direction of society. There have also been many examples of Marxist-Leninist states that have been marked by repression, censorship, and human rights abuses.

Despite its critics, Marxism-Leninism has had a significant impact on world history, particularly in the 20th century. The Soviet Union, China, and many other countries adopted Marxist-Leninist principles and attempted to build socialist states. While the results of these experiments have been mixed, the ideas of Marxism-Leninism continue to inspire socialists around the world who are committed to the struggle for a more just and equal society.