Electric current is defined as the movement of electrons through a medium. The first recorded mention of this is from 600 BC wherein Thales of Miletus discovered that certain materials could hold a static charge. He was unable to explain the phenomena. Electrical current was first harnessed for practical applications by Thomas Edison and Nikola Tesla, experimenting with direct and alternating currents respectively. With the already well-established direct current system in use during the early nineteenth century, it was difficult to convey the advantages of the alternating current system which are especially prominent over long distances. Even today, variant regions of the world use different standards for providing electricity, but it is all done in the forms of alternating current.