Search engine optimization (SEO) is the process of improving the
visibility of a website or a web page in a search engine's "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,[1] news search and industry-specific vertical
search engines.
As an Internet marketing strategy, SEO considers how search engines work,
what people search for, the actual search terms or keywords typed into search
engines and which search engines are preferred by their targeted audience.
Optimizing a website may involve editing its content and HTML and associated
coding to both increase its relevance to specific keywords and to remove
barriers to the indexing activities of search engines. Promoting a site to
increase the number of backlinks, or inbound links, is another SEO tactic.
The acronym "SEOs" can 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 and site content, SEO tactics
may be incorporated into website development and design. The term "search
engine friendly" may be used to describe website designs, menus, content
management systems, images, videos, shopping carts, and other elements that
have been optimized for the purpose of search engine exposure.
The effectiveness of SEO may be measured by the position of a web site on a Search
Engine Results Page (SERP) when searching for a certain keyword, or by web analytic s Key Performance Indexes (KPIs).
source:
http://en.wikipedia.org/wiki/Search_engine_optimization