u/ProlesOfMischief - originally from r/GenZhou
Anarchists traditionally view the state as the source of oppression (including capitalism), and hold that the state must be abolished first of all. A state is a state and therefore a workers' state is no better than a bourgeois state.

Communists argue that the state is the product of class society, and will only disappear when the conditions for its existence disappear. In other words it's no coincidence that the state didn't exist prior to the division of human beings into distinct classes. Furthermore the state is only a tool (in the hands of a ruling class) and has a class character. The goal of communism is to establish the working class as an organized political movement, destroy the bourgeois state, implement its own state apparatus to crush the reactionary capitalist class who will fight tooth and nail to undermine revolution, and once this revolution succeeds in abolishing class generally (i.e. internationally; once socialism has been an established fact for humanity) the state loses its very function as the material basis for the state no longer exists, hence it begins to "wither away".