NASDAQ stands for the National Association of Securities Dealers Automated Quotation System. See why they use the abbreviation? It's much easier for Tom Brokaw to pronounce.

The NASDAQ is a computerized system that facilitates trading and provides up-to-the-minute price quotations on more than 3,200 actively traded stocks. It includes stocks from 35 countries and represents all sectors. The NASDAQ has more trading volume per day than any other stock exchange in the world.

Unlike the New York Stock Exchange, which uses floor traders to execute trade orders, the NASDAQ is completely computer driven. The only sound you'll hear in the NASDAQ offices on trading day is the hum of the computers.

The NASDAQ is traditionally home to many high-tech, high-volatile stocks. There are many big stocks in the exchange, including Microsoft, Intel, Dell and Cisco. In order to be listed on the NASDAQ, a firm must be registered with the Securities and Exchange Commission, employ at least three market makers, and meet minimum requirements for assets, capital, public shares and shareholders.

The NASDAQ composite index (commonly referred to by broadcasters as "the NASDAQ") includes the stock of every company listed on the exchange. The NASDAQ 100 is made up of 100 of the largest non-financial companies listed on the NASDAQ. It does not include foreign companies.