Basically, Capitalism is centered on the Principle of Individual Rights and personal freedoms including the freedom to economically advance while Communism is based on the Principle of Community Rights with no prospect of advancement (for the common citizen). Communist regimes were characterized by the rule of a single party that tolerated no opposition and little dissent.
Current examples of the Communist system are the 5 countries openly identifying as Communist : North Korea, Vietnam, China, Cuba, and Laos.
Brief description:
https://www.worldatlas.com/articles/list-of-communist-countries-today.html