Google wants to display the most relevant website, to its users. For organic rankings, Google looks at over 250 ranking signals and factors when determining who should be placed where. Google will rank the website based on its relevancy, it's credibility and authority to that search term. To succeed in SEO, you need to begin with the content and create a website experience that Google would want to put forward to the search user as a trusted source. At the top of the search results, you will have paid ads. Advertisers are rewarded if their ads are more relevant to the users query, and can potentially pay less on the ad click when they achieve a higher quality score.