Here are some of the definitions of "communism".
Wikipedia: In
political and
social sciences,
communism (from
Latin communis, "common, universal")
[1][2] is the
philosophical,
social,
political, and
economic ideology and
movement whose ultimate goal is the establishment of the
communist society, which is a
socioeconomic order structured upon the
common ownership of the
means of production and the absence of
social classes,
money,
[3][4] and the
state.
[5][6]
Conservatives: Communism is evil and makes everyone poor
People who fled communist regimes: Communism is a police state
Liberal-capitalists: It's a nice idea but it doesn't work in practice because human nature
Tankies: Communism is the USSR and is good actually
PoliSci 101 Freshman who had a US public education: China is communist
Technical: the belief in a society without different social classes in which the methods of production are owned and controlled by all its members and everyone works as much as they can and receives what they need
Actual communists/marxists: Freedom from the shackles of capitalism
Which one of these definitions are valid? They are all valid; all definitions are valid to the person who uses them.