The Dow and the NASDAQ are two of the most widely terms used in reference to the stock market's performance. The Dow Jones Industrial Average (DJIA) and the NASDAQ Composite Index are both classified as indices, benchmarks that track the performance of a particular sector of the stock market.

The DJIA, often referred to as the Dow, is perhaps the most well known index, since it is the oldest and most widely quoted. It is an index of thirty blue chip stocks of U.S. industrial companies. The companies included in the DJIA  have a history of growth and wide investor interest, and they are considered leaders in their respective industries.

Except for transportation and utility companies, which are included on different indices, the DJIA is comprised of a wide range of companies, from financial services to retail companies. The stocks included in the DJIA are chosen by the editors of the Wall Street Journal, a subsidiary of Dow Jones Company, and are not changed very often. The Dow is not a weighted index, meaning market capitalization is not taken into account.

The NASDAQ is both an index and an exchange. When comparing the NASDAQ to the Dow, investors are speaking of the NASDAQ Composite Index. The NASDAQ Composite is one of the most widely followed and quoted major market indexes. It includes over 3000 domestic and international securities that are listed on the NASDAQ exchange.

The NASDAQ is a weighted index, since it takes market capitalization into account. This is used by investors to determine a company's size instead of assets or sales. Market capitalization is calculated by multiplying a company’s outstanding shares by the current market price of one share. The NASDAQ Exchange is composed mainly of technology stocks. Therefore, the NASDAQ Composite may not be a good indicator of the whole stock market, but is a better indicator of technology stocks.