In Electric circuit the End point is always called return because the electrons travel back to the source it came from.
Electric circuit is used by electrons from a current source or voltage power.
A schematic is a diagram of an electrical circuit. Schematics are graphical representations of the essential connections in a circuit, but they are not life-like depictions of a circuit.
One way to make this topic more accessible is to use analogies (Lakoff and Johnson 2008). Analogies are examples which possess similar features, or work in a comparable manner, to the ideas that you wish to teach (Harrison and Coll 2007). They offer an excellent method of visualising difficult and unfamiliar concepts, or ideas that can not be directly seen.