A knowledge graph is a design pattern for storing, organizing, and querying entities and relationships, while a graph database is a type of database specifically designed to store data with relationships. A knowledge graph is built on top of a graph database, providing the structure and meaning to the connected data. Graph databases are ideal for managing connected data, offering advantages such as flexible data models, scalability, and efficient querying capabilities. Knowledge graphs use organizing principles to capture business rules or categories for the data, serving as a flexible conceptual structure that helps surface deeper insights. They are useful for intelligent applications like recommendation engines, fraud detection, and AI systems, providing a strong foundation for use cases involving connected data.