Stock market is a platform for all buyers and sellers to trade their stocks. The buyers and sellers connected to the exchanges through brokers and any selling or buying order is placed through that broker. SEBI regulates the market and questions the required authority when problem arises. The depositors like CDSL and NDSL stranfer the shares from one account to another. NIFT and SSENSEX are used by NSE and BSE to index the companies and give a average trading value of those companies.