Publisher Summary Electrical concepts and theory are of relatively recent origin compared with other fields of science. This chapter provides an overview of a few of the major topics of importance to electrical engineering. The entire field of electrical engineering may be divided into power generation and distribution, electronics and communications, and systems analysis and control. Subjects that are basic to all of these endeavors include principles of conduction, circuit theory, electromagnetic theory, and performance of electrical components. Electronics involves devices and circuits in the design of components such as rectifiers, amplifiers, and control circuits used in radio, sound systems, television, computers, radar, and telecommunications equipment of all sorts. This is a huge area of activity which is changing rapidly, and today many electrical engineers work in this area. Galileo discussed sound waves and their relatively slow speed of movement compared with the speed of light in his works. Galileo pointed out that the speed of light is very much greater than the speed of sound, and described an experiment designed to estimate the speed of light.