The structure of the UPSC Civil Services exam comprises three stages: the Preliminary exam, the Mains, and the Interview. The Preliminary includes two objective papers, focusing on General Studies and aptitude. Those who qualify proceed to the descriptive Mains, which consists of nine papers, including topics like Indian language, English, essay writing, and general studies, testing comprehensive knowledge and analytical ability. The final stage, the Interview, assesses personality traits, communication, and decision-making skills, rounding out the selection process.