Update term explained
Update – meaning the process of updating data in the databases of search engines such as Google, Bing or Yandex. Instead of the full version of this term in the narrow circles is often used a shortened, slang version — Up.
The data upgrade process
During the update, search engines crawl the Internet for the appearance of new pages and also checks previously indexed sites. All received during this process, the information is analysed, the result page is re-ranked, that is, occupy their position in search results for a particular query.
From Google search engine database update happens every day, which leads to the change of the position of sites in the results during the day.
In addition to changing the position of pages in search results can occur:
Checking links on a particular website.
Check changes in the text content of the pages.
Add to base new images.
The change in PR (Page Rank) and TIC (thematic citation index) pages.
Adding a favicon to the database sites.
The exclusion from the index of the mirror sites.
However, the most important for SEO the update is the AP of search algorithms, changing the principles and formulas of ranking of pages in the results.