An electric current is the flow of electric charge. In a metal, the charge carriers are electrons, which are negatively charged. So in a metal, an electric current is the movement of negative charges called electrons.

In other materials, such as semiconductors, the charge carriers can be either electrons or positively charged holes. In a semiconductor, an electric current can be the movement of either negative charges (electrons) or positive charges (holes).

In a vacuum, an electric current can be the movement of either positive charges (ions) or negative charges (electrons).