the flow electrons in a conductor is current.now these days every device and machine need electrical current .electricity is the great invention of modern age and necessary for all where home and commercial use. there is different source to produce electrical energy  first to build a water dam to use water  rotate the turbine which is connected to armature shaft to produce electricity.  

                                                              Another big source of electrical power is thermal energy  which produce pressure to  rotate the armature to produced electricity which is used common in all country's .there is atomic energy,wind energy,solar energy and bio energy very common in developed country's