中文：

道琼斯指数是世界上历史最为悠久的股票指数之一，它的全称为股票价格平均指数。该指数最早是在1884年由道琼斯公司的创始人查尔斯·亨利·道（Charles Henry Dow）所创立的，是世界上最有影响、使用最广的股价指数。

道琼斯指数是一个总括性的市场指标，它涵盖了全球范围内的所有行业和市值为基础的加权平均股票价格。它以股票市场的总市值为基准，通过加权平均的方法计算出每个股票的平均价格。这个指数最初包括12家铁路公司的股票，但现在已经涵盖了全球范围内的所有主要行业和公司。

由于道琼斯指数的特殊地位，它已经成为全球投资者关注的焦点之一。许多投资者将道琼斯指数作为衡量市场表现的重要指标，并使用该指数来评估他们的投资组合的表现。此外，许多公司和媒体机构也使用道琼斯指数来分析和报道市场趋势和经济发展情况。

总的来说，道琼斯指数是一个重要的市场指标，它反映了全球股票市场的整体表现和趋势。它不仅对投资者具有重要意义，也对经济学家、金融分析师和媒体机构具有重要意义。

英文：

The Dow Jones Industrial Average (DJIA), commonly known as the Dow Jones Index, is one of the oldest stock indexes in the world. It is a weighted average of prices of stocks selected for representation of a broad segment of the market. The index is calculated using the weighted average price of 30 large, publicly owned companies that are listed on the New York Stock Exchange (NYSE).

The DJIA was originally designed to reflect the performance of a narrow section of the market, specifically industrial companies. However, it has since expanded its coverage to include all industries and large companies. The index is now a market-weighted index that represents the overall state of the market.

The DJIA is one of the most widely used indicators for tracking the overall performance of the stock market and is watched closely by investors around the world. It is often used as a barometer for the health and direction of the economy, and is a benchmark for many investors to measure the performance of their investment portfolios.

Overall, the Dow Jones Index is a valuable tool for investors and financial professionals to use in assessing market performance and economic trends.