Final answer:
Conventional current flow is the direction that positive charge would flow in a circuit, from the positive to the negative terminal, a convention dating back to Benjamin Franklin. Although it's electrons that move in conductors, the notion of positive charge flow has remained the standard for representing current in diagrams and circuit design.
Step-by-step explanation:
Conventional current flow, also known as hole flow, refers to the direction that positive charge would move through a circuit. This means that in a circuit's diagram, the current is shown flowing from the positive terminal of the battery through the circuit to the negative terminal. The notion of conventional current can be traced back to Benjamin Franklin, who incorrectly assumed the positive charges were the ones moving, not having knowledge of electrons. Despite the discovery that electrons carry the current in many situations and are negatively charged, the convention of positive charge flow direction has persisted.
In metallic conductors like wires, the actual charge carriers are electrons, which move in the opposite direction of the conventional current. However, in other media, such as ionic solutions or nerve cells, both positive and negative charges may constitute current flow. The portrayal of current flow from positive to negative remains a widely used and accepted standard in electrical engineering and circuit design, simplifying the representation of current flow despite the actual motion of electrons.