Depends:
Conventions
The
electrons, the
charge carriers in an electrical circuit, flow in the opposite direction of the
conventional electric current.
The
symbol for a battery in a
circuit diagram.
A flow of positive charges gives the same
electric current, and has the same effect in a circuit, as an equal flow of negative charges in the opposite direction. Since current can be the flow of either positive or negative charges, or both, a convention for the direction of current which is independent of the type of
charge carriers is needed. The direction of
conventional current is defined arbitrarily to be the direction of the flow of positive charges.
In metals, which make up the wires and other conductors in most
electrical circuits, the positive charges are immobile, and the charge carriers are
electrons. Because the electron carries negative charge, the
electron motion in a metal conductor is in the direction opposite to that of conventional (or
electric) current.
Reference direction
When analyzing electrical circuits, the actual direction of current through a specific circuit element is usually unknown. Consequently, each circuit element is assigned a current variable with an arbitrarily chosen
reference direction. This is usually indicated on the circuit diagram with an arrow next to the current variable. When the circuit is solved, the circuit element currents may have positive or negative values. A negative value means that the actual direction of current through that circuit element is opposite that of the chosen reference direction. In electronic circuits, the reference current directions are often chosen so that all currents are toward ground. This often matches conventional current direction, because in many circuits the
power supply voltage is positive with respect to ground.