This book is primarily designed to serve as a textbook for undergraduate students of electrical, electronics, and computer engineering, but can also be used for primer courses across other disciplines of engineering and related sciences. The first edition of this book was published in 2015. The book has been completely revised and a chapter on PSPICE has also been included. The book covers all the fundamentals aspects of electronics engineering, from electronic materials to devices, and then to basic electronic circuits. The topics covered are the basics of electronics, semiconductor diodes, bipolar junction transistors, field-effect transistors, operational amplifiers, switching theory and logic design, electronic instruments, and PSpice. The book is written in a simple narrative style that makes it easy to understand for the first-year students. It includes a lot of illustrative diagrams and examples, to enable students to practice. Each chapter contains a summary followed by questions asked during the University examinations to enable students to practice before the final examination. The contents of this book will be useful also for students and enthusiasts interested in learning about basic electronics without the benefit of formal coursework.