An electric circuit combines electrical components linked in series with a battery or other power source to create a closed loop through which electric current can flow. With their help, we've made tremendous strides in civilization. We have developed machines to perform most manual labor, established global communication networks, and sent a man to the moon in the last century. This has altered our world in fundamental ways. Electric circuits can be organized in several ways. The use of series versus parallel circuits is one such method. The components of a series circuit form a single, unbroken circuit.