Generation of electricity is the first step in the process to deliver electricity to your home. The source of electricity can be generated by a conventional natural gas generator plant, nuclear plant, coal plant, or even from renewable energy such as solar or wind.
Due to the large amounts of electricity, that must flow out from the generator source, transmission lines or large conductors are needed to support the high voltage. These are large power lines that are high off the ground.
Transmission lines then transport the electricity to a substation. Inside the substation transformers step down the amount of voltage which is then carried on the distribution lines to electric consumers.