The Union Public Service Commission (UPSC) is India's premier central recruiting agency that conducts a range of competitive exams to select candidates for various civil services, including the Indian Administrative Service (IAS), Indian Police Service (IPS), Indian Foreign Service (IFS), and other central services.

The UPSC was established on 1 October 1926 under the Government of India Act, 1935, and was later reconstituted as an independent constitutional body under the Constitution of India on 26 January 1950. Its headquarters are located in New Delhi, India.

Since its inception, the UPSC has been responsible for conducting exams and interviews to select eligible candidates for various civil services posts. The commission conducts the Civil Services Examination (CSE) annually, which is considered one of the toughest exams in India.

The CSE consists of three stages: the preliminary exam (objective type), the main exam (written test), and the interview. The preliminary exam consists of two papers, one on general studies and the other on aptitude, which is also known as the Civil Services Aptitude Test (CSAT). The main exam consists of nine papers, including four general studies papers, two optional papers, and one essay paper.

The UPSC also conducts other exams, such as the Combined Defense Services Examination (CDSE), the National Defense Academy (NDA) Examination, and the Indian Forest Service (IFS) Examination.

Overall, the UPSC plays a crucial role in selecting eligible candidates for various civil services posts in India and ensuring the efficient and effective functioning of the government.