Anatomy of a Google Search Engine Results Page, Anatomy of a Google SERP
anatomy of a google search engine results page (SERP)

Google SERP Basic Structure
Organic Search Engine Results - blue box
The organic search engine results are outlined in the blue box. The majority of the number of clicks are tracked usually to the top three positions so it is usually very competitive in order to reach the top position. Organic listings ultimately get a higher number of click throughs by a factor of 8. Listings are determined by a page's number of the queried keyterms, the uniqueness of the content, the popularity of the website and/or page. Google believes that the more relevant and popular a page is, the more likely it is to contain the information that you are searching for.
Sponsored Listings - red box
The sponsored listings in the red boxes on the top and right are placed based upon a complex bidding system. The number of bidders determines the lottery for who will appear on the front page on any given search. Those that don't appear are listed under "More Sponsored Links" (see number 4). The highest bidders have the highest ratio to appear on the front page--the higher a company bids, the more likely they are to appear as a result.
Navigating the Google SERPs
1 - The Search Query
The Green Box outlined at the top of the image is the Search Query. This is where users will type in the information, products, or services they are looking for.
2 - Number of Indexed Results
The number of indexed results determines how many results Google has archived. It doesn't necessarily mean that all of them are relevant. In SEO, it is important to measure the competitiveness of a keyterm or phrase by the number of results listed. If the company that is maintaining a number one position simply has more, unique content, and is an established popular site for the listing, it may be too difficult to beat them out for the top spots. If this is the case, most people turn to Sponsored Listings to ensure that they get visibility on the front page every once in a while.
The best way to determine whether a word is worth competing over is to use Google's Free Keyword Tool to check the number of average searches performed a month on that keyterm of phrase.
3 - Keyterms found in Query Phrase
Google lists the important, relevant terms from your phrase here. Often times general terms people use in their query will not be searched for by Google. (i.e. - the, is, our, that) The list of words that don't get indexed can help you determine whether the content of your site is too broad. If the content isn't unique and targeted, it will have a poor time of appearing on the organic search engine results.
4 - More Sponsored Links
Some keyterms and phrases are just too competitive to have all of the paid listings end up on the front page. This is the main reason why the advertisements are pay per click--you only have to pay google when someone clicks on your link and goes to your site. It's up to you from there to capitalize on them as customers.