SEO stands for search engine optimization. It refers to the process of increasing or enhancing the visibility of a website in search engines like Google, Bing etc by listing them as organic results rather than paid search results. The organic result pages appear on the search engine due to their connection with the search terms. Such results are not classified as pay per click advertisements. Search engine optimization is one of the forms of search engine marketing which involves the promotion of websites on search engines. All other tools that SEM uses such as paid placement, contextual advertising and paid inclusion etc target paid listings.

SEO service is an internet marketing strategy that gives presence to a site. The more repeatedly a site appears in the results listing or the higher it appears on screen the more users will click on the site to visit it. It includes many different kinds of search e.g. video search, image search etc. It further makes it easier to determine the working of search engines and what people commonly search for. One of the tactics used by SEO to promote the site is to edit its content and HTML code to make it more relevant to keywords.

The providers of this service are called search engine optimizers. This term refers to the industry of consultants who perform SEO services. As mentioned above, the task requires making suitable alterations in the site content or HTML code. Thus, it is a part of website development and design. Precise functions of SEO service providers include reviewing the structure of the content, offering technical recommendations on website development, managing online campaigns, offering their expertise in specific areas and markets along with a few others.

While SEO services may prove to be valuable for generating revenues, making a wrong choice in this case can bring counterproductive results. Incorporating such content in a website that violates the seo company may eventually cause the removal of the site. This leads to the categorization of SEO techniques, techniques that increase the positive promotion of websites and techniques that minimize the popularity of a site. These categories have been named by some as white hat SEO and black hat SEO respectively. White hat methods include services that follow the rules and ensure that the content that an engine indexes will be the same as viewed by the user and is easily accessible. Black hat methods include immoral practices such as using hidden text, or using a color similar to the background. This may result in the web site being banned by an engine.