Madeleine Leininger's Theory of Culture Care Diversity and Universality focuses on how culture influences health, illness, and caring behaviors. The theory posits that care is essential to health and is influenced by cultural factors. Leininger developed the Sunrise Model and three modes of culturally congruent care to guide nursing practice in a culturally sensitive manner. The theory transformed nursing by highlighting the importance of understanding culture to effectively care for patients from diverse backgrounds.