Search engine optimization or SEO is a collection of marketing strategy techniques used to increase the rankings and visibility of a web site or web page in search engines and aggregated news sources such as Google News. Search engine optimizers are specialists who perform SEO services for clients with the goal of growing the traffic to a web site due to improved search engine rankings.

A web site that is buried low in the rankings on a search engine will receive significantly less traffic than one that is ranked highly. Web sites which have high enough rankings to be listed on the first page of a search engine under their primary marking keywords receive the most traffic. Competition for these top rankings are extremely fierce. Thus, having a web site properly reviewed and revised for prime search engine optimization can be vitally important for the success of that site.

When optimizing a site for higher search engine ranking and visibility, an SEO professional focuses on how a consumer organically uses a search engine to locate information. This includes discovering what the prime keywords or phrases a person would use to look for the information contained on the web site being optimized.

One of the primary techniques of search engine optimization is to increase the density of these prime keywords on the targeted web site or web page. For example, if the web site is geared toward selling customized surfboards, an SEO expert would focus on making sure related search keywords -- such as surfing equipment and custom surfboards -- were prominent in the content and coding of the site. Having a large amount of content on a web site related to the desired marketing keywords can dramatically help increase a web site's search engine rankings.

Search engine optimization specialists also use a technique called 'backlinking' to help increase a web site's search engine rankings. The term 'backlinking' refers to the online marketing strategy of having direct links to the website placed on other related web sites. Some search engines, such as Google, strongly consider the amount of incoming links to a web site in determining search engine ranking. A web site should have as many inbound links from well-ranked, content rich web sites as possible to increase its rankings in the search engines.

SEO also includes the art of ensuring the coding of a web site is optimized for crawling by search engines and new aggregators. This means that when a search engine robot comes to the web site, it should be able to locate and index all of the site's content easily under its prime keywords and phrases. A simple mistake in the coding of a web site can prevent it from being properly indexed, which could mean a significant loss in traffic and customers. This kind of search engine optimization makes sure that all content on the web site, including articles, images, videos, etc. are coded to be indexed successfully when the site is crawled by a search engine. A web site that has been optimized in such a way are often described as being 'search engine friendly' and this can dramatically increase the traffic to a web site from search engine and news aggregator sources.

Any web site that wishes to have a truly successful presence in search engines or aggregated news sources should be reviewed and revised for maximum search engine optimization by an SEO expert. Having a site properly optimized for the highest search engine rankings possible can make an extreme difference in the amount of traffic, advertising revenue or direct sales that site generates.