The concept of electric current

In electromagnetism, the amount of electricity that passes through any cross section of a conductor per unit time is called current intensity, or simply electric current. The symbol for current is I, and the unit is ampere (A), or simply “A” (André-Marie Ampère, 1775-1836, French physicist and chemist, who made outstanding achievements in the study of electromagnetic effects and also made contributions to mathematics and physics. The international unit of electric current, ampere, is named after his surname).
[1] The regular directional movement of free charges in a conductor under the action of the electric field force forms an electric current.
[2] In electricity, it is stipulated that the direction of the directional flow of positive charges is the direction of the current. In addition, in engineering, the directional flow direction of positive charges is also used as the direction of the current. The magnitude of the current is expressed by the charge Q flowing through the cross section of the conductor per unit time, which is called the current intensity.
[3] There are many types of carriers in nature that carry electric charge. For example: movable electrons in conductors, ions in electrolytes, electrons and ions in plasma, and quarks in hadrons. The movement of these carriers forms an electric current.