In Marxism, the dictatorship of the proletariat is a type of state or government where the working class control the state. It is also known by names like socialist state, proletarian state, and other names. A dictatorship of the proletariat is the opposite of a dictatorship of the bourgeoisie, where business owners and the wealthy control the state.
Karl Marx and Friedrich Engels, two very important communist thinkers, believed that the dictatorship of the proletariat would be a time between capitalism and communism. They thought that if the workers took power in their country and took over the means of production (like factories and farms) that communism could be made. They believed that eventually, classes, the state and money would not exist anymore, or need to exist anymore.
The dictatorship of the proletariat is called a dictatorship because under that type of society, the working class have all power over the state and other classes, like the bourgeoisie, don't have any. Many communists believe that in order to keep power in the country, the dictatorship of the proletariat has to be authoritarian, or use its authority to oppress the enemies of the working class.