SEBI began as a non-statutory body set up by a government resolution before an Act made it statutory
Background
The Securities and Exchange Board of India records on its own site that it was constituted as a non-statutory body on April 12, 1988 through a resolution of the Government of India.
It was established as a statutory body in the year 1992.
The provisions of the Securities and Exchange Board of India Act, 1992 (15 of 1992) came into force on January 30, 1992.
The Preamble of the Securities and Exchange Board of India describes its basic functions as being to protect the interests of investors in securities, to promote the development of the securities market, and to regulate the securities market.
Appeals against the Board's orders lie to the Securities Appellate Tribunal.
In plain words
SEBI Securities and Exchange Board of India — The statutory regulator of India's securities market.
SAT Securities Appellate Tribunal — The tribunal that hears appeals against orders of the Board.