The soil level on a washing machine indicates the amount of dirt and grime present in the clothes being washed. It ranges from light, for lightly soiled clothes, to heavy, for heavily soiled items. Understanding the soil level is crucial for effective washing, as it helps determine the appropriate water temperature, wash cycle duration, and amount of detergent required. The washer’s soil sensor detects the soil level and adjusts the settings accordingly, ensuring optimal cleaning while preserving fabrics.