There is no difference between a square power socket and a round power socket, only the appearance is different. The pins and sockets must comply with relevant standards.
In addition, the square and round pins are subject to different standards in various countries and regions, and sockets and plugs must be of the same standard. There are fifteen socket and plug standards around the world. When traveling to different countries and regions, you must bring a conversion plug.
For example, the United States has two flats (parallel) and one circle, Australia has two flats (eight-shaped) and three flats, mainland China has two (parallel) flats and three flats, and Germany has two circles and three circles.