Electricity can be produced in several ways, such as at plants that burn coal or natural gas, hydroelectric plants that use the force of rushing water, and nuclear plants that split atoms. The energy produced goes through a generator, which in turn makes electricity.
From the generator, the electricity is sent over transmission lines to a substation. A substation lowers the voltage so that it can be distributed to your home. From the substation, the electricity travels through distribution lines to a pole transformer. In places where lines are underground, a green pad mounted transformer is used to lower the voltage once again before the electricity enters your home.