In electrical circuits, conventional current flow is defined as the flow of positive charge from the positive terminal of a voltage source to the negative terminal. However, historically, it was initially assumed that positive charges flowed, and this convention has stuck.

In reality, electrons, which are negatively charged, are the charge carriers in most materials, and they move from the negative terminal to the positive terminal of a voltage source. This movement of electrons constitutes an electric current.

The reason for the historical convention of positive charge flow is rooted in the early understanding of electricity. When scientists were first investigating electrical phenomena, they didn’t know about the existence of electrons. They observed the movement of positive ions in electrolytes and assumed that positive charges were moving.

Later, when the discovery of electrons and their role in electric current became clear, the convention had already been established. To maintain consistency in electrical theory and avoid confusion, the convention of positive charge flow was retained.

In summary, while electrons (negatively charged) are the actual carriers of electric current in most materials, the convention of positive charge flow is used for historical and conventional reasons. This convention doesn’t affect the actual behavior of electrons in a closed circuit; it’s simply a matter of established terminology and consistency in the field of electrical engineering.

Later, when the discovery of electrons and their role in electric current became clear, the convention had already been established. To maintain consistency in electrical theory and avoid confusion, the convention of positive charge flow was retained.

In summary, while electrons (negatively charged) are the actual carriers of electric current in most materials, the convention of positive charge flow is used for historical and conventional reasons. This convention doesn’t affect the actual behavior of electrons in a closed circuit; it’s simply a matter of established terminology and consistency in the field of electrical engineering.