louieramos - 4:15 am on Jun 9, 2010 (gmt 0) [edited by: louieramos at 4:23 am (utc) on Jun 9, 2010]
The way Google is indexing pages, filtering duplicate contents, differentiating between quality content and content farms, paid links etc affects the SERP of each sites, these are all part of the new algorithm of Google, and all these factors I have mentioned are part of Google Caffeine.
Google Caffeine is the overall program. PHP and MySQL are not the same thing nor part of each other, they are different entities. To correct your analogy "PHP + MySQL = Overall Program". PHP and MySQL can be anything from algorithm change, structure change, indexing change and whatever is involved in this whole caffeine thing.
Caffeine is a way of delivering new and more accurate search results to the public and the algorithm is a big factor in doing this.
[edited by: louieramos at 4:23 am (utc) on Jun 9, 2010]