The official Google Webmaster Blog has released details of a major update to Google, code named “Caffeine.” Basically “Caffeine” is an update to the search engine’s code and although these happen quite frequently this large code update warrents a press release and a bit of hype in their book. Google claims only “power users” will really see the difference and are asking for their feedback on the new infrastructure from them. Currently the update is live only on a testing sandbox address: www2.sandbox.google.com.
This update allows Google to index more documents faster, and display them to you, the user, faster. Of course they have also tweaked the ranking algorithm and the importance of sites such as Wikipedia has been dowengraded very slightly. Universal search has also been demoted slightly, instead of image, news and video results at the top of the page these will usually appear lower down the page on “Caffeine” powered searches. Books and Shopping results are also noticeably absent although these may return once the new code is put onto the live Google servers.
Search Engine Watch blog has some excellent comparison screenshots.
Google’s Matt Cutts explains a bit more about the update at the SES Conference in San Jose to Web Pro News: