All the major search engines will produce primary search results to its users for an individual’s unique enquiry. Google, Bing and Yahoo will give results such as video, web pages or local listings and these will be shown and ranked based on what the search engines deem to be most relevant. It is differernt from Paid Ads as the results cost the owner of the result nothing.
On Page Optimisation
Webopedia: In search engine optimization, on-page optimization refers to factors that have an effect on your Web site or Web page listing in natural search results. These factors are controlled by you or by coding on your page. Examples of on-page optimization include actual HTML code, meta tags, keyword placement and keyword density.
Off Page Optimisation
Webopedia; In search engine optimization, off-page optimization refers to factors that have an effect on your Web site or Web page listing in natural search results. These factors are off-site in that they are not controlled by you or the coding on your page. Examples of off-page optimization include things such as link popularity and page rank.
Webopedia: In search engine optimization (SEO) terminology link building is the process of exchanging links with other Web sites to increase your own site’s backlinks and quality backlinks.