Many web owners end up confused about the rankings for their site, and never realize it. The confusion arises from the fact that often links on Google™, Yahoo™, and Bing™, point to the home page of the site. Yet, it is your web pages that are ranked not your site. So how is it that so many of the links from the search engines point to the home page.
The short answer is navigation. Undoubtedly every page on your site has a link in the menu, or in the logo, or other places to your home page. Probably every page has multiple links to your home page. With these links, every page on your site is casting “votes” onto the home page. The search engines tally these “votes”. Then each in its own way, they translate this such that when you search for a phrase (your key phrase) a set of links come up. The weight that each search engine gives all its different measurements ends up with your home page often representing the weights of several other pages in the site. It may seem as if the search engines ranked your entire site, but the reality is that many of your sites pages have added their “votes” together in such a way that it is your home page that appears first in the rankings ie. the search engine return pages (SERPs).