Here is a picture of a PECO transformer. High voltage power is fed into this device and it is stepped down to the voltages that you find in your home. The exact voltage will change depending on how close your home is to the transformer. Most homes have between 110 and 120 volts in their main panel box on each of the power legs. Here power is similar to water pressure. Just like some homes have better water pressure than others, some homes have a higher electrical current running through them. It all depends on their distance from the source.
