In journalism, the inverted pyramid refers to a story structure where the most important information (or what might even be considered the conclusion) is presented first. The who, what, when, where and why appear at the start of a story, followed by supporting details and background information.
The inverted pyramid is a metaphor used by journalists and other writers to illustrate how information should be prioritised and structured in prose (e.g., a news report). It is a common method for writing news stories and has wide adaptability to other kinds of texts, such as blogs, editorial columns and marketing factsheets.
This writing style gets to the point quickly and supports all types of readers. Even those who have the time or inclination to read only a single paragraph, or even a single sentence will still know what the story is about.
This principle also applies to posts on X-Ray Magazine's website, and for news in the magazine.
The inverted pyramid also helps editors when they need to cut a piece at a certain length to fit a publication: if the paragraphs get less and less important as you advance in the article, the article can easily be trimmed at practically any point.
More details in this good article: Inverted Pyramid: Writing for Comprehension