UPSC Jobs for 24 different Civil Services are filled through Civil Service Examination (CSE) conducted by Union Public Service Commission. Out of lakhs of aspirants, only a few thousand students can successfully clear this examination. Although there are 23 different Civil Services, the most popular services are Indian Administrative Services (IAS), Indian Police Services (IPS), Indian Revenue Services (IRS) and Indian Foreign Services (IFS). The allotment of services to successful candidates depends on the rankings obtained in the examination. A candidate after getting selected in service is appointed to various posts (in the span of his career) within that service except in some cases where he/she may go on deputation to another department in another service.