As marching into the digital era, many people in different sectors are quite keen to understand why this has happened. They hope to obtain basic principles about digital signals and associated digital systems. Instead of targeting advanced or expert level, they often hope to grasp the subject as efficient and effective as possible without undertaking impossible task under usually limited time and effort available. This book is written for those beginners who want to gain an overview of the topic, understand the basic methods and know how to deal with basic digital signals and systems.