DC is the acronym of English direct current, which means: direct current, referred to as direct current or direct current.
History of development of alternating current: alternating current was first invented by inventor nikola tesla. 1888, Tesla got the support of George Westinghouse, an entrepreneur of Westinghouse Electric Company, and started the research and development of alternating current for six years.
Half a year later, he applied for a patent for his "alternator" and invited the American Institute of Electrical Engineers to publish and demonstrate the research results of "AC" power generation.
William Stanley designed the first practical and effective AC transformer conversion device.
Development history of direct current: Early engineers mainly devoted themselves to the research of direct current, and the power supply range of power stations was limited, mainly used for lighting, not as industrial electricity.