From that wikipedia entry: " socialism is a stage of society in Marxist theory transitional between capitalism and communism".
Read the Manifesto for yourself. Communism is the ultimate utopia where the state withers away. There has never been a true communist state, nor can there be, (at least according the the Manifesto).
That's why I always grit my teeth everytime I hear China's government reffered to as "communist". They have a Communist party, but the governement is far from communism. There are many wealthy Chinese real estate owners, and manufacturing plant owners, and private customs brokers as well. The government owns a lot of industry too. But to call them "communist" is as inaccurate as calling the USA "capitalist".