The Internet search engine Google has a huge database of various Internet data centers. Every month Google updates / re-indexes its database. Due to the size, it cannot simultaneously post a new index at all the data centers. If you happen to enter the same query repeatedly while Google is in the process of posting the index at various data centers, it might seem like the results are inconsistent. Whata™s actually happening is that you are seeing a result from an a˜olda™ version of index once and a result from the a˜newa™ version the next for a short period of time. Different search results in different Google search indices (google.com, www2.google.com, www3.google.com) is called Google dance.