SEO has been around since the web was conceived as we know it in 1995.
The history of SEO
In February of 2011, Google released the first of a series of major changes in their algorithm, called Panda, and it’s main focus was to clean the database of farm linking
websites and sites with duplicate content erasing them from Google’s index list. This change was applied first on the US and later worldwide. Many sites with top positions were affected Panda, mainly because their content was poor, they were linking farm sites or many of their internal pages had duplicate content.