Search engine optimization (SEO)
is 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 relevance, SEO considers
how search algorithms work and for what people search. SEO efforts may
involve a site's coding, presentation, and structure, as well as fixing
problems that could prevent search engine indexing programs from fully
spidering a site. Other, more noticeable efforts may include adding
unique content to a site, ensuring that content is easily indexed by
search engine robots, and making the site more appealing to users.
Another class of techniques, known as "Black hat" SEO or spamdexing, use
methods such as link farms and keyword stuffing that tend to harm
search engine user experience. Search engines look for sites that employ
these techniques and may remove their listings.
The
acronym "SEO" can also refer to "search engine optimizers", a term
adopted by an industry of consultants who carry out optimization
projects on behalf of clients, and by employees who perform SEO services
in-house. Search engine optimizers may offer SEO as a stand-alone
service or as a part of a broader marketing campaign. Because effective
SEO may require changes to the HTML source code of a site, SEO tactics
may be incorporated into web site development and design. The term
"search engine friendly" may be used to describe web site designs,
menus, content management systems and shopping carts that are easy to
optimize.