The 'google dance' is the phenomenon of sites going up and down quickly in serps when there's a major update happening. - Used to be a big feature when major updates were a 'big event - slightly mythical, these days, I would have thought, as updates are happening all the time
Google dance refers to the period of time when Google indices are tuned. This will often cause both a fluctuation in index size as well a significant change in a web site's search result position. you can see google dance tool here seochat.com/googledance
Whenever Google make some updation in its indexing and ranking process, it starts dancing i.e. Google Dancing...
When google dance strike your site, you'll going to noticed that your SERP goes up and down and sometimes it is nowhere to be found. But usually you'll get back close to your original positions but sometimes not. and that's the worse thing that happened to my site way back then.
Maybe someone should teach you how to use Google first, then you can answer these simple questions for yourself.
We can not say Google dancing for each and every seconds, if you find your website ranked on 1st page on Google and after 1 or 2 days your website won;t be there till 50 pages in se's. than u can say it;s some what dance. If you find rankings for keyword like "online payment" than there is bit more competition, so one who works hardly and good, will be there on top. otherwise one can easily lost his rankings.
Theres a google dance tool you can use to check out your keywords and see how they range. Just search for it on google.