This document provides an introduction to interior design. It discusses interior spaces, interior displays, and the importance of interior design. It explains that interior design enhances functionality, aesthetics, and reflects lifestyle. The document also outlines the process of interior design and discusses research, programming, design development, and post-occupancy evaluation. Finally, it covers key design principles like scale, proportion, balance, rhythm, emphasis, and harmony as well as elements of interior design such as space, shape, form, line, texture, pattern, light, and color.