What do you mean by Sensex and Nifty?

For your information first time BSE called (Bombay stock Exchange) introduce the word sensex.word Sensex made from tow word sensitive+index. Similarly NSE Called (National Stock Exchange) also introduce nifty.Word Nifty made from to word National+Fifty.Sensex and nifty is nothing but a index which seems us the difference in stock market between yesterday and today.
There are 31 companies registered in sensex. so we can say that sensex depends on 31 companies gain or loss. Similarly There are 50 companies registered in nifty. So we also say that nifty depends on 50 companies margin or loss.sensex and nifty also depends on other factors like currency,Other countries Stock Exchanges, and there are so many other factors like politics and market situation. So we can't say that what is the future of indian stock market but we assume that the near future of the market in India.
Basically main factor of dependence is which amounts of people who interested to buy stock in market and who interested to sell there stocks.for your information you assume that when the amounts of buyers is higher then market gones higher and when the amounts of sellers is higher then market gones downside.