What is the name for a pathway that allows current to flow from the positive terminal to the negative terminal of a power source?

The correct term for a pathway that allows current to flow from the positive terminal to the negative terminal of a power source is a circuit. A circuit provides a closed loop through which electric current can travel, enabling the flow of electrons from the power source (like a battery or generator) to any connected devices, and back again to the source, thus completing the circuit.

In a circuit, components such as resistors, capacitors, and inductors may be included to control the flow or manipulation of electricity, but the fundamental concept remains that the circuit itself is where the current flows. Resistors specifically limit current, transformers change voltage levels, and inductors store energy in a magnetic field, none of which define the complete pathway used by electric current in the context of the question.