There are many search engines today, but few are the ones that could be considered as powerful. Google is definitely a leader in this area and since the start of Google back in the early 1998, the company updated their algorithms many times and reaching up to 500 — 600 updates per year lately.
Almost every month there is a major update that has effect on the search engine ranking results. Toolbar PageRank (TBPR) is considered by some SEOs as the application that gave start to the search engine optimization. Over the years, the Google Company releases different algorithm changes and new applications all in the name of the easier search and better results.
Some of the changes made over the years are: filtering the content and removing the low quality one, personalizing the search so it can be easier for the normal user to find the information desired and presenting few new successful hits like Google Chrome web browser. The Google + network is one of the major moves in the history of Google as they made their own social network.