In what way is communism a higher stage of socialism?

I consider that socialism is the stage of society that follows capitalism. it is the time of the eradication of capitalist ways of creating society (way of production, etc.), behaving (wars to get resources, lands, markets) and the establishment of cooperative ways. I think that this period could be quite long, "ironing out the bugs," so to say, of what has been created by capitalist and feudalist society before it. Later, after a process of "settling," society will further transform. Communism is a later result.