The Henry Draper Catalogue is a comprehensive star catalog that classifies stars based on their spectra. Created by the American astronomer Henry Draper in the late 19th century, it includes detailed observations of over 200,000 stars. The catalog is significant for its role in the development of stellar classification and astrophysics. The catalog is organized into different spectral types, which helps astronomers understand the physical properties of stars, such as temperature and composition. It laid the groundwork for future catalogs, including the Harvard Classification Scheme, and remains a valuable resource in the field of astronomy.