Vintage

Search engine optimization (SEO) is the process of improving the  amount of traffic to a website from search engines (like Google)  via organic search results.

Organic search results are non-paid search results.  For example, if you type a search phrase on Google you'll get 2 types of results.  The first is paid results (Sponsored Listings) and the second are organic search results.  Organic search results are the results that Google displays based on what you searched for.  Since these are not paid results, Google delivers what they feel to be the most relevant results, in order or importance.