Jekyll has two concepts for content, pages and posts. They start with a few lines of YAML preface, followed by content written in one of the markdown languages that Jekyll supports. Both can include template code, and both are interpreted by Jekyll and converted to html. These results are copied into the _site directory. Content placed in the _posts directory gets additional care and processing, to be converted to pages that are listed chronologically on the home page. This is what it means by Jekyll being “blog aware” out of the box.

Any markdown files in the root or its subdirectories with a YAML preface will be processed as pages. Pages appear in the site as static pages the the location they appear in the directory hierarchy. Also, the theme that comes with Jekyll lists all pages it’s processed in the common header shown on each page. This is where the about page link is shown. (If you have a lot of static pages this is not necessarily what you would want for the rest of your page contents.)