"Classification - the ubiquitous challenge" is a comprehensive academic book that addresses the challenges and applications of classification in various social contexts. It is based on the proceedings of the 28th annual conference of the Society for Classification e.V., which took place at the University of Dortmund. The book offers a detailed analysis and discussion on the role of classification in technology and computer science, particularly in the field of programming. With a wide range of topics and contributions from experts in the field, it serves as a valuable resource for students, researchers, and professionals interested in the theoretical and practical aspects of classification. The publication is written in English and provides a solid foundation for understanding the complex relationships in classification.