The examination that precedes the UPSC Main Examination is the UPSC Preliminary Examination, which serves as a qualifying test. The Preliminary consists of two papers: General Studies I, which covers a wide range of topics, and General Studies II (often referred to as CSAT), which assesses comprehension and analytical skills. Only those who qualify in the Preliminary are eligible for the Mains. The Preliminary serves as a crucial filter, and thus thorough preparation is essential to progress to the next stage of the UPSC Civil Services Examination.