Digital Electronics is practically dominating other electronics branches ever since the development of digital computers. The speed is further accelerated with the use of digital electronics in satellite and mobile communication. With mobile phones, digital electronics is being used by everyone. With this background, it was thought to write a simplified book in digital electronics. It has been written in a student friendly style. Starting with different number systems, digital gates, their uses, various laws for simplification of digital circuits are discussed with interactive approach, in initial chapters of the book. New techniques and approaches are used for solving certain problems. Concepts are illustrated with number of problems and diagrams. Counters, Registers, A/D, D/A Converters are explained in latter part of the book. We are confident that the book will be useful for understanding basics of digital electronics by all working in the field of science, engineering etc.