What actually is current? Why does it differ from potential difference?

Current is defined as 'the flow of electric charge'. It can be broken down into very simple system of electrons, who carry charge, moving around a circuit. Potential difference can be thought of the force that is required to make these electrons move around the circuit. It can almost be considered a pressure that squeezes the electrons, causing current to flow in the circuit. So, whilst Voltage/potential difference is most commonly thought of in circuitry, its actually the current that provides the physical electrical energy to components.