From its beginnings in the late nineteenth century, electrical engineering has blossomed from focusing on electrical circuits for power, telegraphy and telephony to focusing on a much broader range of disciplines. However, the underlying themes are relevant today: Power creation and transmission and information have been the underlying themes of electrical engineering for a century and a half. This text concentrates on the latter theme: the representation, manipulation, transmission, and reception of information by electrical means. This book describes what information is, how engineers quantify information, and how electrical signals represent information. This book describes the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to lessen the possibility of misunderstandings at a higher level. The difference between linear and non-linear operation is explored through the use of a variety of circuit examples including amplifiers constructed with operational amplifiers as the fundamental component and elementary digital logic gates constructed with various transistor types. Fundamentals of Electronics has been designed primarily for use in an upper division course in electronics for electrical engineering students. Typically such a course spans a full academic years consisting of two semesters or three quarters. As such, Electronic Devices and Circuit Applications, and the following two books, Amplifiers: Analysis and Design and Active Filters and Amplifier Frequency Response, form an appropriate body of material for such a course. Secondary applications include the use in a one-semester electronics course for engineers or as a reference for practicing engineers. Electronics has undergone important and rapid developments over the last 60 years, which have generated a large range of theoretical and practical notions. This book presents a comprehensive treatise of the evolution of electronics for the reader to grasp both fundamental concepts and the associated practical applications through examples. It is the intention of this text is to teach the fundamental operation of basic electronic components by comparison to drawings of equivalent mechanical parts. It must be understood that the mechanical circuits would operate much slower than their electronic counterparts and one-to-one correlation can never be achieved. The comparisons will, however, give an insight to each of the fundamental electronic components used in every electronic product.