Theoretical clarifications regarding the polarity of the concept of Church

This paper presents a sociological point of view but also the theological definition of the Church. Thus treated various aspects involved in the concept of the Church, namely: Community nature versus institutional character, unity and universality, divine nature and human nature, visible and invisible depiction of the Church. There are also presented here principles of organization of the Orthodox Church and aspects of the structure of the Orthodox Church and the Romanian Orthodox Church.