There is a regular page rank update of all leading search engines. This method ensures the timeliness of the page rank of websites. Within this update, the search engine recalculates in accordance with its own algorithmic formulas each page in the index. This certainly leads to changes in the result lists. These changes are not in real time on the site of the search engine, but initially only done within a toolbar. The real value will be assigned only later to the website of the search engine.