Hi Samuel, There are about 200 factors that rank sites.
The competition chart shows you overall analytics, but you need a more in depth audit in order to see why someone is really outranking your site.
Search ensines look at: Links, social media, relevancy, natural progressions, and easy crawlability. They are also looking for bad signals: over optimization and unnaturally linking.
We look to see what our competition is doing just to create ideas to put into play, or to create a better piece of content that they have written about.