How Do Electrons Move in Little Circles?

How can something conduct only on the surfacey, it's really interesting. It has to do with how electrons move. And so we talk previously about insulators being when electrons are stuck. So now imagine a material where electrons aren't quite stuck. They're not exactly stuck on one atom but they can sort of like moving little circles. But if electrons are moving in a circle, then think about what happens on the surface,. Instead of having electrons move in little loops, their loops are sort of like cut in half. That doesn't allow this to conduct electricity. Because there's no effective flow of electricity.