Communism vs. Socialism

From time to time I become unsure what I and others are talking about when we refer to Communism or socialism.  Here is an article gathering a few different takes.  My summary is that Communism has come to describe the totalitarian-style states of the late 20th century Iron Curtain, while socialism more broadly refers to any organizations of economic production by means other than a laissez-faire market.  In this sense, almost all countries have lots of socialist aspects of their economies, like public schools, roads, healthcare, social security, price controls for certain products and services, etc.  But there are only a handful of Communist countries left in the world (Laos, Cuba, North Korea, China, and Vietnam, to be specific).