An electric circuit is a closed path through which the electric current flows. It can have various components such as battery, resistors, wire, keys and much more, which can be connected in different ways.
A simple electric circuit will be one which contains the basic elements like a bulb, a resistor, a battery and a switch.
An electric circuit is said to be broken if there is a break in the path of current. This can happen when a the key in the circuit is open or if the switch is turned off. In such cases, current in not able to pass through the break.