Google Dance is when your ranking for a search term move. One search your website may show up as position #3. The next search, it may be on page 2, position 15. Your listing is dancing.
Google Dance was the term used to describe the period that a major index update of the Google search engine are being implemented.
The name "Google Dance" has often been used to describe the index update of the Google search engine. Google's index update occurred on average once per month. During an index update there was significant movement in search results and Google showed new backward links for pages.
It is the change of rank for your site from 1st position to any position in google search. Google tries to find the correct position for our site based on the keyword and the content. Basically the change is very large for newer site when compare to old sites.
