An electric circuit is a path in which electrons from a voltage or current source flow.
The circuit breaker will open, or "break", the circuit when the current in that circuit becomes too high, or the fuse will "blow". This gives protection.
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”).
Electric circuitry is a key component of the National Curriculum, particularly from ages 14, Key Stages 4 onwards. However this is a difficult concept to teach because it of its abstract nature.