The stock market works by playing a part in the network of economic transactions. Its main function is to trade company shares, and you may check out the website http://en.wikipedia.org/wiki/Stock_market for more information.
Many companies are listed on stock market, buyers buy the shares or stock while sellers sell their shares on it and try to make money. The important thing is to take right decision at right time for that you can take help from broking agents. http://www.religareonline.com/