Whats the difference between the DJI and NASDAQ?

From Wikipedia:
The NASDAQ (acronym for National Association of Securities Dealers Automated Quotations system) is an American stock market. It was founded in 1971 by the National Association of Securities Dealers (NASD). It is the largest electronic screen-based equity securities market in the United States, with approximately 3,200 companies. Smaller capitalized companies as well as many young start-ups can be found there.

A key word in that definition is "...AN American Stock market". Although there are several other smaller ones, the most recognized stock exchanges in the US are the New York Stock Exchange (NYSE), the American Stock Exchange (AMEX) and the NASDAQ.

The Dow Jones industrials on the other hand, is an index of the 30 largest and most widely held companies on the NYSE, or what might be called "blue chip" stocks: everything from 3M to Coca Cola to GM to Disney. It is "currently a scaled average, not the actual average of the prices of its component stocks%u2014the sum of the component prices is divided by a divisor, which changes over time, to generate the value of the index."
(wikipedia)

List of 30 DJI stocks change occasionally as stats change, while the Nasdaq stays mostly the same ....the preponderance of tech stocks are on the Nasdaq: viz; MSFT, DELL, CISCO, INTEL, ORACLE, LUCENT, VERISIGN.

osakarob very good answer

The Dow Jones industrial average is a product of the Dow Jones Company and is intended to represent the overall market when a company changes, becomes irrelevent, merges, or spins off. they find a replacement to take it’s place. When they do this they try to adjust the new entry to the one leaving. It used to be a straight average but over the years splits and replacements have forced it to adjust the components to keep the charts relevent and usefull.

They also have a transportation average that when compared with the industrial average was supposed to help evaluate the future direction or condition of the market.