Whole foods are unprocessed or minimally processed foods, retaining their natural state, while processed foods undergo various treatments, often containing additives like sugars and preservatives. Whole foods include fruits, vegetables, nuts, and grains, providing essential nutrients and benefits such as better overall health. In contrast, processed foods may lead to poor health outcomes, including obesity and chronic diseases, due to their calorie-dense and nutrient-poor nature. The key difference lies in their nutritional value and effects on health.