What does AC stand for in ACDC?

Hello there, could you please clarify what the acronym "AC" stands for in the popular band name "ACDC"? I'm genuinely curious as to what inspired the band to choose such a name, and how it relates to their music or perhaps their origins. Perhaps it's a reference to something specific, or maybe it simply sounded cool at the time? I'd love to know more about the history behind this intriguing name.