Step-by-step explanation:
At a power plant, there is a production of electricity at a high voltage compared to the voltage provided to our home.
The step-up and step-down transformers are used to convert high voltage to low voltage. The step-up transformer provides high voltage and low current at a power plant and the step-down transformer is used to provide low voltage to home.
The voltage of the electricity that leaves the plant compare to the voltage of the electricity as it enters your home from high voltage to the low voltage.