In this process there is improvement in the volume and quality of web sites. The process of improving the volume and quality of traffic to a web site from search engines via "natural" ("organic" or "algorithmic") search results. Usually, the earlier a site is presented in the search results, or the higher it "ranks," the more searchers will visit that site. SEO can also target different kinds of search, including image search, local search, and industry-specific vertical search engines.

As a marketing strategy for increasing a site's relevancy, it considers how search algorithms work. SEO involve a site's coding, presentation, and structure, as well as problems that could prevent search engine indexing program .It also include adding unique content to a site, and making sure that the content is easily indexed by search engines.

Search engine optimizers offer SEO as a stand-alone service of a broader marketing campaign. Because SEO may require changes to the HTML source code of a site. This may be used to describe web site designs, content management systems and shopping carts.