This bottom panel of wood covers up the standing structures of the base cabinets. When installing multiple cabinets, a single long toe kick can make the set of cabinets look like a cohesive unit.
The toe kick area is slightly more recessed than the rest of the counter so that a person can stand closer to the counter while they work. While toe kicks unify the look of the cabinet and seem purely decorative, those who want to maximize their space may install toe kick drawers. These shallow drawers at the bottom of the base cabinets create additional storage and are used for various items depending on size.