Google Caffeine vs Decaf

Google Caffeine, which has been going through rigorous testing within Google and on various datacenters for the past ten months. This long-awaited update brings a reportedly 50% faster indexing system than on previous versions of Google, as well as even faster search results for users.

The difference between Google Caffeine and "decaf" versions of Google is that now, web content is indexed in pieces, whereas before it was indexed in "layers." This new system allows new web pages and new content to be indexed almost immediately, rather than waiting several days or weeks as happened before. In fact, Google reports there will be hundreds of thousands of gigabytes of new data added per day; this new indexing system comes at a time when online media types are changing and content such as images and video are becoming more prevalent. This update also comes on the heels of Google's latest "facelift," where the Google logo was changed, more search options added, and most recently, users are able to change the image on their Google homepage (so it appears much like Bing's).

in reference to: Google (view on Google Sidewiki)