What is Google Dance & when it occurs?

Search engines in one way or other need to index or categorize web pages based on some criteria so that the search results is reliable to the user who searches for the contents. As google became a popular search engine the importance to site indexing by google was given a great hype.

Google dance is the time period when google sends its spiders to crawl a website to check for its contents, it is said to be happening once in a month, nobody has got any better idea about when google is indexing the web pages. In recent times indexing is done regularly. At this point of time the ranking of a website can fluctuate or dances, when checked on the servers in the data centers of google. Chances of a higher ranked website getting disappeared all of a sudden from (SERP) or Search Engine Resulting Pages is more.

Google has got several data centers and servers now and the google sends its spiders to check the websites from any of these servers. These spiders check for any change in the content of the website even a minor change is reflected as it checks for relevancy of the content and so many other factors like back links, fresh content, keywords, coding standards, domain names, etc.
   

Google regularly sends a crawler usually known as a “Fresh Crawler” to get the fresh content updated in a website. At longer interval a “Main crawler” checks the data collected by the “Fresh Crawler” as well as the old content already stored in the data centers. Based on both the old and new content as well as the relevancy of the website, the index and page ranks of a website are determined by Google. At the same time the “Main Crawler” updates this information in all data centers of google spread across the globe one by one this time period is called “Google Dance”.

Google usually indexes the pages after a “Google Dance” with an appropriate page rank purely based on the criteria’s google requires. Most of the webmasters look at “Google Dance” with wide open eyes as it’s all about how a website is getting indexed with the worlds number one search engine.
Reference: http://buildmylink.com/articles/Google-Dance.html