- Federalism A system of government where power is divided between a central authority and constituent political units. It aims to preserve regional identities while ensuring national unity. - Pluralistic Model A model of nation-building that recognizes and respects the diversity of identities (cultural, linguistic, regional) within a state and seeks to integrate them within a common political framework. - India's federal structure is a key mechanism for managing its vast diversity and pursuing a pluralistic approach to nation-building.