Search-engine optimization (SEO) ::
is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic"). 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.
is a form of internet marketing that seeks to promote websites by increasing their visibility in search engine result pages (SERPs) through the use of paid placement, contextual advertising, and paid inclusion. Search Engine Optimisation (SEO) "optimises" website content to achieve a higher ranking in search results, for example, by incorporating specific keywords or links associated with the website. Depending on the context, SEM can be an umbrella term for various means of marketing a website including SEO, or it may contrast with SEO, focusing on just paid components.