Kelvin–Stokes theorem

Kelvin–Stokes theorem is like a law of nature for electromagnetic fields. It's a way of understanding how electricity and magnetism interact with each other. Think of it like a big equation that scientists use to figure out things about electricity and magnetism. Basically, the equation says that when electricity and magnetism meet, something new is created. This something new is called a magnetic field. So when electricity passes through a magnet, it creates a magnetic field around it that can be measured and studied.