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.[1]
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,[2] 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.[citation needed] 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.[3]
As an Internet marketing strategy, SEO considers how search engines work, the computer-programmed algorithms that dictate search engine behavior, what people search for, the actual search terms or keywords typed into search engines, and which search engines are preferred by their targeted audience. SEO is performed because a website will receive more visitors from a search engine the higher the website ranks in the search engine results page (SERP). These visitors can then be converted into customers.[4]
SEO differs from local search engine optimization in that the latter is focused on optimizing a business' online presence so that its web pages will be displayed by search engines when a user enters a local search for its products or services. The former instead is more focused on national or international searches.
The leading search engines, such as Google, Bing and Yahoo! use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. The Yahoo! Directory and DMOZ, two major directories which closed in 2014 and 2017 respectively, both required manual submission and human editorial review.[40] Google offers Google Search Console, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that are not discoverable by automatically following links[41] in addition to their URL submission console.[42] Yahoo! Formerly operated a paid submission service that guaranteed crawling for a cost per click;[43] however, this practice was discontinued in 2009.
Search engine crawlers may look at a number of different factors when crawling a site. Not every page is indexed by the search engines. The distance of pages from the root directory of a site may also be a factor in whether or not pages get crawled.[44]
Today, most people are searching on Google using a mobile device.[45] In November 2016, Google announced a major change to the way crawling websites and started to make their index mobile-first, which means the mobile version of your website becomes the starting point for what Google includes in their index.[46]
