What does electrical current flow consist of?

The flow of electrical current primarily involves the movement of electrons through a conductor. When an electrical potential is applied across a conductor, it creates an electric field that causes free electrons, which are typically found in the outer shells of atoms, to move. This movement of electrons from one atom to adjacent atoms constitutes electrical current.

The other options describe phenomena that do not accurately reflect how electrical current functions. Protons are positively charged particles found within the nucleus of an atom and do not move freely in conductive materials to create current. Neutrons are neutral particles also located within an atom's nucleus and do not contribute to the flow of electrical current. Lastly, while magnetic fields are a result of electric current, they do not themselves flow through a conductor as electrical current does. Instead, magnetic fields are created by moving charges (electrons) but are distinct from the flow of current itself.