AC vs DC : direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically. The voltage in AC circuits also periodically reverses because the current changes direction.Alternating current describes the flow of charge that changes direction periodically. As a result, the voltage level also reverses along with the current. AC is used to deliver power to houses, office buildings, etc.Direct current is a bit easier to understand than alternating current. Rather than oscillating back and forth, DC provides a constant voltage or current.
Edison and the beginning of modern Science: Although Edison (1847-1931) is best known as the inventor of the incandescent light bulb, the phonograph, and the motion picture, these innovations are a fraction of Edison's legacy. More than 85 years after his death, his accomplishments in the field of industrial research and development still resonate with scientists and engineers.