Stock Markets Exposed - When I hear on the news the stock market is up or down so many points, what is exactly is a point?

When I hear on the news the stock market is up or down so many points, what is exactly is a point?

If the stock market index was at 5,000 yesterday and today it is 5,001 - it went up 1 point. If it goes to 5,010 tomorrow, it has gained 9 points. You get comparisons from the start of the year, the month, the day and sometimes even the hour. It gives you an idea of how confidence in the economy or certain stocks and shares is held by the people with money.........
The most popular index is the Dow Jones Industrial Average (DJIA) which includes 30 representative companies. When people talk about the market up so many points, they are usually talking about the DJIA.