This book provides the basic concepts of electronic digital communication, applied to professional practice in communications engineering. The book begins with basic concepts of information theory and explains the need for digital communications, continuing with the basic schemes of digital communication prior to multiplexing, which applies to current digital communication networks, such as LTE, 5G and 6G. The book is intended for researchers, professionals, and second-year students of electrical engineering, electronics or telecommunications. It can also be useful to students in computer science, engineering physics or other disciplines who develop projects involving electronic communication systems. Presents the basic concepts of electronic digital communication, applied to practice in communications engineering; Provides a bridge between students and professionals in telecommunications engineering; Includes basic concepts of information theory and explains the need for digital communications.