The purpose of the CSAT (Civil Services Aptitude Test) paper in the UPSC Preliminary Examination is to evaluate candidates on their comprehension, logical reasoning, analytical ability, and basic numerical skills. This paper assesses the candidates' competency in understanding and interpreting data, which is essential for effective decision-making in public administration. While it is a qualifying paper, scoring well is crucial, as it ensures candidates can proceed to the Mains stage, where their knowledge and understanding of various subjects are tested in detail.