There are three hoses connected to your washing machine. They are the hot water hose, the cold water hose, and the drain hose.
The hot water hose brings water through the water heater and into the washing machine for washing your white laundry. Make sure you separate your whites from the dark and colored clothing so that the bleach that you use in your white load of laundry doesn’t ruin your dark and colored clothing.
The cold water hose bypasses the water heater. It is used for washing dark clothing so that the pigment does not fade.