A share market is where shares bought and sold by the public.
A stock may be bought or sold only if it is listed on an exchange. Stock Exchange is the meeting place of the stock buyers and sellers. Bombay Stock Exchange(BSE) and the National Stock Exchange(NSE) are major two exchanges in India. These two stock markets are controlled by SEBI(Securities and Exchange Board of India)
Sensex is the market index consisting of 30 well-established and financially sound companies listed on Bombay Stock Exchange (BSE). Nifty is the market index consisting of 50 well-established and financially sound companies listed on National Stock Exchange of India (NSE).They are calculated by the averages of the existing companies in the group.
IPO is an initial public offering. It is the very first sale of stock issued by a company to the public. One can apply for for IPO both through offline by filling application form and online through demat account