I'm in 8th grade and have no qualms about admitting that I have zero understanding of how electrical currents work. I understand that theres a rotating magnet but thats about it. I'm doing a paper on Nikola Tesla and the biography I'm reading says he invented a poly-phase current, "In the beginning, out of the obligations towards investors, he had to work in the area of carbon arc lights, but after that he started realizing his projects in the area of poly-phase alternating currents." My paper has absolutely nothing to do with said current however I would rather understand what I'm writing about than have a name with no explanation.