The UPSC introduced the CSAT exam as part of the Prelims in the year 2011. The Civil Services Aptitude Test was implemented to evaluate candidates' logical reasoning, analytical ability, and comprehension skills, thus enhancing the selection process. This addition aimed to assess candidates' basic understanding rather than mere memorization of facts. Since its inception, CSAT has become a crucial element of the UPSC Prelims, impacting the overall preparation strategy of aspirants who need to balance both general studies and CSAT for effective results.