I thought I'd start the week with a reminder of an oldie but goodie. This document came out after the intial barrage of "what is cloud computing" and "cloud computing defined" posts from a few years ago. But, I've always felt that NIST did a great job with it overall.
In my opinion it's still one of the best and most complete current definitions of Cloud Computing of any other out there. So, in the off chance that you have not seen this defintion of cloud computing it is definately worth the time to read through.
One of my earliest definition articles from April 2008, Get Your Head in the Clouds, is still my most trafficked article on this site most weeks.
"Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is composed of five essential characteristics, three service models, and four deployment models..." --NIST Cloud Definition
In particular I like the way they break down the characteristics, service, and deployment models.