Electric circuits are different than electronic circuits.
The point where those electrons enter an electrical circuit is called the "source" of electrons. The point where the electrons leave an electrical circuit is called the "return" or "earth ground". The exit point is called the "return" because electrons always end up at the source when they complete the path of an electrical circuit.
The electrons enters from a point to an electrical circuit which is called the “source” of electrons or “electrons source” . The point where electrons leaves the circuit is called ground or earth(in some concepts it is also know as “return”).
During project days or workshops contact time with students is limited. It is therefore important for us to quickly ascertain student level of knowledge and then build on it or reinforce it. Analogies provide a good method of finding out students pre-existing level of understanding on this topic.