2) Nifty is the leading index for large companies on the NSE. The Nifty is a well diversified 50 stock index accounting for 21 sectors of the economy.
3) The Nifty Junior represents the 100 most liquid commodities traded on the NSE.
4) A demat a/c stands for dematerialised account. Just as you have to open an account with a bank if you want to save your money, make cheque payments etc, you need to open a demat account if you want to buy or sell stocks. So it is just like a bank account where actual money is replaced by shares.
5) Depository Participant is the agent of the Depository and is the medium through which the shares are held in the electronic form. They are also the representatives of the investor, providing the link between the investor and the company through the Depository.
6)Permanent Account Number (PAN) is a ten-digit alphanumeric number, issued in the form of a laminated card, by the Income Tax Department.
7) Day trading refers to the practice of buying and selling shares within the same trading day such that all positions will usually (not necessarily always) be closed before the market close of the trading day.
Prepared by qblp web research team for PSC aspirants from wikipedia and income tax dept site.