A current flows around a circuit because the cell, which is the source of the current, forces it to do so. The terminal of the cell can be considered to be at different 'electrical pressures', more correctly termed 'electrical potential'. As in water, where the difference is pressure causes water to flow from a high pressure area to a low pressure area.An electric current can continually flow along a wire only if the wire forms a complete path or circuit. As the current travels along a continuous circle of wire it goes all the way around and arrives back at the start or source. This whole arrangement is called an electric circuit.
There are two types of circuits series and parallel circuits.
A series circuit type of circuit, that the components are arranged end to end.If there's a gap in a series circuit or maybe one of the components has broken, the current can't flow and so, the whole circuit turns off.
In a parallel circuit,the components don't have to be end to end because the circuit can have branches.If there's a gap or broken component in one of the branches of a parallel circuit, the components in other branches will carry on working.