Transformers are used to increase or decrease voltage supplies.
Transformers consist of two sets of windings where one winding induces a bigger or smaller voltage in the secondary winding.
An example of this is the transformer (possibly outside your property) used to reduce the voltage coming from the power lines from 11,000 volts to 230 volts. This high voltage transformer will be managed by your lines company.
Transformers are also used with a variety of appliances and electronics to reduce the voltage from the power outlet (230 volts) down to a smaller voltage such as 24 volts. Transforming voltages down is important if you want to install anything electrical in a wet area.
