There are many ways of organizing news stories, or in other words, there are many basic structures on which the content of news stories is based. However, the most prominent or the most commonly used style of writing news is based on the Inverted Pyramid structure.
According to this structure, news stories are organised in such a way that the most important or most interesting part of the news is told first. This usually refers to that kind of information which is important to the reader, and he/she would want to know about it first. All questions of who, what, when, where, why and how are answered here.
After this, usually the details are given. This part of a news story usually reflects that information which is used to substantiate the beginning part. And then this is followed by some conclusion, or the least important bit of information, that winds up or ends the news story.
Thus, the inverted pyramid structure basically organizes the information in an order of diminishing importance, with the most important information first, and the least important information at the end.