The main goals of the traditional communist party are: to overthrow the bourgeois state, to establish a communist proletariat dictatorship and to collectivize the means of production.
The bourgeois state is a state controlled by the bourgeois classes, which in a capitalist economy are the ones who own the means of production, like factories. A proletariat dictatorship is a political and economic system where the means of production are in the hands of the workers, not the bourgeois. In a communist economy there is no private property, instead, property is public, which means is in the hands of a Communist state.
This end, according to the Communist Manifesto and Das Kapital both written by Karl Marx and Friederich Engels, can only be achieved by a proletariat revolution, that implies that every worker from the world shall unite and organize against the bourgeois classes in order to take the power and replace the capitalist world system for a communist global economy.
Is important to note that a real communist system, according to orthodox Marxism, can only be achieved in industrial societies, since the masses of industrial workers are the ones who will overthrow the capitalist industrial system. Marx also said that this revolution would happen eventually since it is part of a historical cycle of class struggle and that capitalism has, in its main core, the seed of its own destruction.
In the 20th century there were several revolutions that followed these concepts throughout the world, but with different approaches and applications and not precisely in industrial countries. Today there are many political parties that call themselves communist and participate in democratic elections and not necessarily call for a revolution to take power and achieve their goals.
