The article presents the criteria employed in distinguishing languages and, within the framework of structuralist and sociolinguistic perspectives, delves into the role of identification criteria in the context of the Croatian language. Through a critical analysis of the interpretation of various criteria in Croatian linguistics, the article uncovers the issue of arbitrariness in language differentiation. The author asserts that, as a product of society, language cannot exist without its specific cultural context and, therefore, concurs with the thesis that language is inevitably influenced by politics. Within the scope of the Croatian language, the article examines several differentiation criteria, including structural, genetic, standardization, mutual intelligibility, and, notably, the identification criterion. The latter appears to be the least ambiguous, aligning with the principle that a language belongs to the entire community of its speakers. However, practical application raises certain challenges.