Without beating much around the bush let me get straight to the point. The UPSC exam is a 3-phase affair:
Phase 1 is the UPSC Preliminary Examination, also called UPSC Prelims. This exam contains questions of the objective type.
Phase 2 is the UPSC Mains Examination, also called UPSC Mains. This exam contains descriptive-type questions.
Phase 3 is the Personal Interview round conducted to test the Personality of the Candidate.
 
To give you a brief about the UPSC syllabus, let me tell you, that the IAS syllabus comes along with the official notification of UPSC CSE.
 
While there are three phases adjoined with recruitment, the syllabus is defined for only two stages, the Prelims, and the mains. More about the IAS syllabus 2022 in the following sections.
 
Oh, and if by any chance you want to directly get to know the UPSC Syllabus without going through the article, I have prepared for you a UPSC syllabus PDF. In this PDF of the UPSC syllabus, I have mentioned the syllabus of both, Prelims and Mains in much detail.
Read more: UPSC Syllabus