Identity is one of the central points that give subjectivity, direction, and meaning to contemporary politics. It is the basis of identity politics, which embodies the interests and hopes of many groups in society, but at the same time causes many misunderstandings, confusions, tensions and conflicts. In this chapter, we answer the questions: what is identity? How is it studied in sociology? What are the most important sociological theories that conceptualize identity? What types of identity exist? In doing so, we perceive identity on two levels. On the first level, we determine identity through a sociological perspective. On the second level, we determine identity on the basis of the subjectivity that it induces, which can be personal, situational, and social.