There are over 3000 company symbols in the stock market. Every symbol represents a company. The reason why they do not use the full company name is that it would make the listing too long. The symbols are used on Electronic ticker tape which can be seen in many places such as the NYSE, various cable channels and at Times Square in Manhattan. Symbols were made so anyone who was interested in buying stock, or already bought stock, would be able to see the stock's status.

The link below leads to a web site where you may look up any company's symbol or the symbol for a certain company.