A while back @Waldyrious posed this question about WikiApiary. https://twitter.com/waldyrious/status/441123248999108609
The full answer is actually found in my talk page on WikiApiary. Articles are a construct that each wiki can manage. MediaWiki tries to create these two classes of content: Pages and Articles. The intent being that pages are in some way less like "content" than articles. The metrics for determining this are configurable, but I’m guessing nearly everyone leaves it at the defaults. I felt that the page concept, just looking at content and not judging if it was better or worse was a simpler way to look at thousands of different wikis.