Great question! Electrons create a current of electricity when they move. To understand an electric current one needs to understand the basics of an electron. An electron is an elementary particle that carries a negative charge. Electrons much of the time surround the nucleus of an atom. When electrons are located inside a conductor, particularly metals, they can move relatively freely inside the metal. Identical charges repel each other and opposite charges attract. Electrons are negatively charged and move toward positive charges. When one side of the metal is more positively charged than the other side the electrons will move in that direction. The motion of the electrons creates an electric current. Below is a sketch showing the basic principles.