Define an electric circuit. Distinguish between an open and a closed circuit.

(N/A) An electric circuit is a continuous and closed path along which an electric current flows.
An open circuit is a circuit in which the path is broken or the switch is in the $OFF$ position,preventing the flow of current.
$A$ closed circuit is a circuit in which the path is complete and the switch is in the $ON$ position,allowing the electric current to flow continuously.