Rather than attempt to superficially cover every aspect of circuits and devices, this practical new introduction focuses on device modeling, circuit operation and analysis, and applied design in a way that establishes an understanding of how devices fundamentals can be applied in a wide range of circumstances. Basic devices are introduced through a two-chapter format that consists of a first chapter dealing with the particular device category and its models, followed by a second chapter dealing with simplified applications that use only resistive components. Prior to examining transistor amplifier circuits, a general development of amplifiers from a block diagram point of view is presented; and, concepts such as gain, input resistance, output resistance, stage loading, and interaction are developed with simple models before students become involved in specific circuit details. Manufacturers' specification/data sheets are used throughout the coverage.