Cameron Watt clearly explains the difference between authoritarian and libertarian socialists, and argues in favor of libertarian socialism (=anarchism).
The difference between democratic socialism and revolutionary socialism
Socialism in all forms strives to improve the economic life of the downtrodden people — the homeless, the poor. And this can be done only by political means. Democratic socialists hope to do this through parliaments, through congresses of representatives or deputies. Revolutionary socialists, by contrast, think this can be done only by changing the political institutions.
Authoritarian socialists think this can be done by their party taking control of the central government. The assumption is that a central government (i.e. the State) is necessary to do this. In the Soviet Union there was no socialism; there was State capitalism. The government took over the factories and farms and hired wage-workers. And these products entered into the international market.
Libertarian socialists, by contrast, want to get rid of a central government altogether, i.e., the State, and replace it with a federation of small communities governed by democratically elected councils.