License Plate 60318 How Does The License Plate System Work In America?

How does the license plate system work in America? - license plate 60318

I've always been curious about how the system works the plate the United States? What happens if you have multiple vehicles? I've heard that the board is not connected to the driver, is that true? Also, the nature of the technical controls you in the United States? In the United Kingdom have what we call an ITV, where the brakes, steering, safety, lighting and emissions test on an annual basis, the United States have nothing of all this?