Breadcrumbs
At the top of each article, there is list indicating the current category, along with a trail (of breadcrumbs) indicating how many levels lead back to the Homepage (indicated by the Home icon)
This list of breadcrumbs can be helpful when navigating through lots of articles, since they may be located in different categories or locations in the category tree.
Clicking on one of the breadcrumb segments, such as "Creating Content" above, will take you to the Category List view for that specific category, listing all of the articles associated within it.
If you click on the Home icon or name, you will be returned to the homepage, which is a known starting point if you get disoriented while browsing articles.
Breadcrumbs will automatically be generated as new categories and articles are created, so you don't need to explicitly do anything with them, but knowing they are there can be helpful at times.