The significance of the CSAT paper in the UPSC Civil Services Preliminary Examination lies in its role as a qualifying exam. While it tests mathematical and comprehension skills, its main purpose is to ensure candidates possess essential aptitude for civil services. The CSAT carries less weight than General Studies Paper I but is mandatory to qualify for the main examination. A certain percentage is required to clear this paper, compelling candidates to prepare adequately. Proficiency in CSAT enables candidates to demonstrate critical reasoning and problem-solving abilities essential for administrative roles.