Social identity represents the dynamic product developed by the individual, based on social categorization processes, which is subject to change and conflict phenomena. The individual's social identity contributes to his self-definition and holds a central position in group relations. It is a key concept, with the help of which we try to examine how sociological factors, psychological factors and their outcome contribute to the dynamic structuring of the personality of the individual interacting in a very wide range of social roles. The work represents a theoretical study with reference to the particularities of social identity, through the prism of different approaches of different authors.