Whole foods are not heavily processed. That means whole, unrefined, or minimally refined ingredients including whole grains, vegetables, fruits, and legumes. Think whole potatoes vs. potato chips.
Plant-based means foods which are derived from plants only.
Whole-Food Plant-Based doesn’t include animal products such as meat, milk, eggs, or honey or heavily processed foods such as white rice, white flour, artificial sweeteners, high fructose corn syrup or oils. (An olive is a whole food while the oil that has been removed from the olive is a processed food.)