Whenever we use some search engine we always see a lot of related web pages which belong to different websites. Ever thought what do the owners of these websites pay the search engines to refer them to you? Well this is where search engine optimization (SEO) comes in. SEO is the process which affects the visibility of a web page whenever we use some search engine. SEO is a magical and priceless thing for the websites owners as higher the rank of the web pages or the more the web pages appear in search results, the more will be the number of visitors on the website.