Search engine optimization(SEO) is the process of improving the visibility of awebsiteor aweb pageinsearch enginesvia the "natural" or un-paid ("organic" or "algorithmic")search results. Other forms ofsearch engine marketing(SEM) target paid listings. In general, the earlier (or higher on the 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, includingimage search,local search,video search, news search and industry-specificvertical searchengines.