In this book, a theoretical framework (validated by experiments) is introduced in the form of a number of white-box analytic or semi-analytic mathematical models that are based on physics. These models will provide the intuition needed by device engineers, display engineers, manufacturing engineers, and metrology engineers working in the fields of displays and data communication, which will help them design and manufacture optimal devices for each application. The book also provides models for display systems and data communication systems to help system engineers understand and assess the gaps between commercially available MicroLEDs versus what is needed for a specific system. The book is designed for engineers who want to start with physics-based intuition to design MicroLED-based systems within ~80% accuracy, then follow with running experiments and more sophisticated models to capture the top 20% of design accuracy. This 80-20 approach is proven to work in many fields including the semiconductor industry.