Algorithms are computer programs that seek clues to offer you exactly what you want. For the normal request there are thousands, maybe even millions of web pages with useful information. Algorithms are computer procedures and formulas to your question turn in answers. Today, Google algorithms rely on more than 200 unique signals or “clues” that allow us to discover what we are really looking for.
Each year, Google changes its search algorithm around 500–600 times. While most of these changes are minor, Google occasionally rolls out a “major” algorithmic update (such as Google Panda and Google Penguin) that affects search results in significant ways.
Whenever there’s a significant update to the Google algorithm, search marketers all across the board go crazy. Everyone first goes into a tizzy to see if their clients have been affected, and then to publish their own hypotheses on the nature of the update and how to ride it unscathed. For search marketers, knowing the dates of these Google updates can help explain changes in rankings and organic website traffic and ultimately improve search engine optimization.
In the infographics below you will see the most important Google algorithm updates of 2015. How they affected the different branches of online businesses and the growing of their significance: