The Death Of SEO: The Rise of Social, PR, And Real Content - Forbes | SEO Daily Dose | Scoop.it
There is internal and external SEO. Internal makes up about 15% of the process and it means to design your site so it follows the best practices proven to rank high on Google. External SEO used to mean to write articles, press releases, blogs, comments, and content with embedded keyword “backlinks” to your site. Now it is changing fast to include social media strategies.

Via Alex Butler