I visited Vietnam over the summer and I believe they are still under Communism. I dont know much about it though.
its the philosophical, social, political and economic ideology and movement whose ultimate goal is the establishment of the communist society, 
Are there a lot of countries under communism?
The goal is the establishment of socioeconomic order structured upon the common ownership of the means of production and the absence of social classes, money and the state.
I see. When was this ideology first conceived?
Communism includes a variety of schools of thought, which broadly include Marxism, anarchism ,a type of ideology
I had no idea it was that diverse. Has the concept been around for a long time?
Like communism ,we have Socialism is a range of economic and social systems characterised by social ownership and democratic control of the means of production
Interesting. What else can you tell me about Communism? Is it still popular around the world?
Its based on the assumption that. analysis that the current order of society stems from its economic system, capitalism; that in this system there are two major social classes: the working class