Google crawls and updates its index every day and the term “everflux” is used to describe the constant state of low-level changes which are not announced as Google Update.

Google updates its index data, including backlinks and PageRank, continuously. Google also crawls and updates its index every day. If the changes brought about are low-level they are called “everflux” and are not usually announced as updates. Only once in three months big changes are announced as updates.

Google engineer Matt Cutts disucsses ‘Gadgets, Google, and SEO’ in his blog
and he uses the term “everflux” for the low-level changes that are part of a regular indexing program.

According to Matt Cutts, “what registers with an update to the webmaster community is when we update an algorithm (or its data), change our scoring algorithms, or switch over to a new piece of infrastructure. Technically Update Gilligan is just backlink/PageRank data becoming visible once more, not a real update.”

The number of backlinks a website has refers to the number of other websites linking to this one. And PageRank refers to the position in a list of websites listed when a key word is typed by a user, in a search engine.