An electrical contractor in Austin, TX, posted a super-informative blog post about understanding AC and DC electrical currents. This is what the differences boil down to: "DC" means "direct current".

Power relays are specifically designed to handle either AC or DC. It’s important to know the fundamental differences between them before building them into a system. Introduction to AC and DC Power ...

As the story goes, the rock band AC/DC took its name from a label on an old sewing machine in the Young brothers’ home. It must have meant that the machine could run on either alternating-current or ...