Search engine optimization (SEO) is the process of increasing the quality and quantity of website traffic by increasing the visibility of a website or a web page to users of a web search engine.
SEO refers to the improvement of unpaid results (known as "natural" or "organic" results) and excludes direct traffic/visitors and the purchase of paid placement.
SEO may target different kinds of searches, including image search, video search, academic search, news search, and industry-specific vertical search engines.
Optimizing a website may involve editing its content, adding content, and modifying HTML and associated coding to both increase its relevance to specific keywords and remove barriers to the indexing activities of search engines like Google ,Yahoo etc. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.