Online and offline study materials each have their pros and cons for UPSC preparation. Online resources offer flexibility, instant updates, and interactive formats that can enhance engagement. They also provide access to a wide range of content, including video lectures and quizzes. However, offline materials, such as books and handwritten notes, may promote better retention due to tactile learning and reduced screen fatigue. The choice between these modes often depends on personal learning styles, but a balanced approach utilizing both can optimize preparation.