It is a term which is used in Search engine optimization (SEO). Fluctuation in the rankings of websites on Google's Search Engine Results' Page(SERP) is called Google Dance which is an outdated term now. rankings of Web sites on Google's SERP may fluctuate in order during several day periods. The "Google Dance" would happen anywhere up to 36 times per year.
Google Dance is an out-dated slang term used to describe the period of time in which Google used to rebuild its rankings, and as a result of this rebuilding, rankings of Web sites on Google's SERP may fluctuate in order during a several day period.
Google has described it as being a dance of sorts, because the changes are slowly released, causing search engine result fluctuation until the next indexing and recalculation.