Search engine optimization (SEO) is the process of affecting the visibility of a website or a web page in a search engine's "natural" or un-paid organic search results.
In general, the earlier (or higher ranked on the search results page),  and more frequently a site appears in the search results list, the more  visitors it will receive from the search engine's users. 
SEO may target  different kinds of search, including image search, local search, video search, academic search, news search and industry-specific vertical search engines.
As an Internet marketing  strategy, SEO considers how search engines work, what people search  for, the actual search terms or keywords typed into search engines and  which search engines are preferred by their targeted audience.  Optimizing a website may involve editing its content, HTML and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic.
The plural of the abbreviation SEO can refer to "search engine optimizers," those who provide SEO service.
 

 
