The pre-wash cycle will agitate heavily soiled clothing to try to shake loose most of the dirt before the actual washing takes place. It will be much more likely to remove dirt and stains.
The prewash cycle is a feature that washes, drains and rinses the clothes before the normal washing cycle begins. This feature is usually used for heavily soiled clothes.
The pre-wash cycle prepares the clothing in a washing machine for all of the subsequent washing cycles. This gets the clothes soaking wet and submersed in detergent.
