When someone wants for the electricity to go through one path to the destination, a series circuit is probably the best way to go. The series circuit is organized so that the current is not interrupted by other pathways.
Electricians often come across this problem because they want the current to go directly to the appliance. If a customer is having trouble, then it may not be a series circuit or it was routed poorly. Other than series circuits are the parallel circuits.
This is important to know which one is needed because they serve two different functions. If a series circuit has unequal resistances throughout the circuit, the lowest resistance has the highest voltage. Voltage can best be described as the difference between the electricity in two places.