The UPSC CSE (Civil Services Examination) is conducted in three stages – Preliminary Exam, Main Exam, and Personality Test (Interview). The Preliminary Exam is the first stage, followed by the Main Exam, and then the Personality Test. The Preliminary Exam is a screening test and is objective in nature, while the Main Exam is subjective in nature and tests the depth of knowledge and understanding of the candidate. The Personality Test (Interview) is a test of the candidate’s personality traits, communication skills, and overall suitability for a career in the civil services.  
About Prelims Exam: Some information about the UPSC CSE Prelims exam along with syllabus and marks distribution: The Prelims exam consists of two papers : 1. General Studies Paper-I2. CSAT (Civil Services Aptitude Test) Paper-II. Here’s the syllabus and marks distribution for the UPSC CSE Prelims exam:
Paper Subject Syllabus Marks
Paper-I General Studies - Current events of national and international importance
- History of India and the Indian National Movement
- Indian and World Geography
- Indian Polity and Governance
- Economic and Social Development
- Environmental Ecology, Biodiversity and Climate Change
- General Science
Paper-II CSAT (Civil Services Aptitude Test) - Comprehension
- Interpersonal skills including communication skills
- Logical reasoning and analytical ability
- Decision-making and problem-solving
- General mental ability
- Basic numeracy (numbers and their relations, orders of magnitude, etc.) (Class X level)
- Data interpretation (charts, graphs, tables, data sufficiency, etc. - Class X level)
Both papers are of objective type and each paper carries a maximum of 200 marks. The duration of each paper is two hours. The CSAT Paper-II is qualifying in nature and candidates need to score a minimum of 33% marks to qualify for the Mains exam. Only the marks obtained in Paper-I will be considered for selecting candidates for the Mains exam.