Direction of Electric Current

Direction of Electron Flow:

Electrons flow in a conductor (in the circuit outside of the voltage source) from the negative of the source where electrons are in surplus to the positive pole where there is a relative deficit. Inside the source the electrons are forced away from the positive pole towards the negative. (see graphic below). The source ensures that there is always a potential difference between the two poles. 

Basic Electrical Properties

To avoid one frequently made error, it needs to be pointed out that the electrons are not actually created by the source; the source merely sets existing free electrons in the conductors of the circuit in motion. Similarly the electrical devices being powered, that are generally called "loads" (e.g. the lamp in the above circuit),  do not actually "use up" electrons. What they do use is some of the energy that the moving electrons carry.

Direction of Conventional Current:

Before the theory of electrons came to be known, even though the terminology, 'positive' and 'negative', had been chosen arbitrarily, it was assumed that any carrier of current was actually in excess at the positive pole and in deficit at the negative so that current would flow from positive to negative. Despite the more recent knowledge about electricity, the assumptions about the direction of flow had been become so established that it was thought practical to stick to the convention that current flows towards the negative pole. Thus the direction of an electric current is, by convention, in the opposite direction to the electron flow. It is common to speak of conventional current in this respect. The following graphic illustrates what this means. 

Basic Electrical Properties

To sum up:

Electric current flows by convention from positive pole to negative pole in any circuit external to a voltage source.

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