In this video, we look at the definition of voltage, current, and power from a qualitative and quantitative perspective. We use the water analogy to represent the flow of electrons as the flow of water molecules. Voltage can be thought of as a pressure difference between two sides of the same pipe. Current is similar to the flow of water, and only happens when there is a voltage difference. Power is the product of voltage and current. More detail is given in the lecture video below.
If you have any questions, please feel free to leave a comment and I will be happy to answer them.
AXElectronic 