Visual representations reflecting the order and structure of knowledge have been used for hundreds of years. In the current digital age, many modern computerized approaches have allowed for innovative visual deliveries of information and knowledge in addition to the long-standing, inherent fundamental structures and theories of knowledge representation. This presentation focuses on the hierarchical structures of knowledge organization, aiming to connect theories and practices for certain structures, norms, and best practices, explores their variances in applications with or without quantitative measurements, and discusses the functions of visual representation methods and layouts that enable consequential information discovery and ultimate user experience in the data-driven age.