Social sites is primarily sites with  services that provides  social functions on simple interfaces where you just fill out your own  profile form and then you are ready to start contributing without having knowledge in HTML codes. If you had many several bookmarks that you thought were interesting and you would like share them with others, you could send an email or instant message to a friend or post the links on their web page that is called SEO because you linking back your sites there it allows you also to give a short description of the page or other item that you are bookmarking and let the community for review.

It is similar to bookmarking is the ability to save and categorize a personal collection of bookmarks and share them with others. Bookmarking is a relatively new technology that has changed the way people experience the Web by allowing users to store, classify, rate, comment on and search links to any website or blog.  Social bookmarking is rapidly becoming a very effective means for experienced web surfers to find the latest information on a particular subject and helps SEO a website it helps also to expose your web content to a lot of users, especially to those who are interested in the same topics or subjects that your site is offering.