It is the infrastructural paradigm shift that is sweeping across the Enterprise IT world, but how is it best defined? I refer of course to 'Cloud Computing' - the phenomenon that currently has as many definitions as there are squares on a chess-board. To try and narrow it down we bring here a round-up of some recent attempts to bring welcome precision where there risks being unnecessary vagueness. Enjoy!

"What is cloud computing all about? Amazon has coined the word “elasticity” which gives a good idea about the key features: you can scale your infrastructure on demand within minutes or even seconds, instead of days or weeks, thereby avoiding under-utilization (idle servers) and over-utilization (blue screen) of in-house resources. With monitoring and increasing automation of resource provisioning we might one day wake up in a world where we don’t have to care about scaling our Web applications because they can do it alone."
-Markus Klems

"For me the simplest explanation for cloud computing is describing it as, 'internet centric software.' This new cloud computing software model is a shift from the traditional single tenant approach to software development to that of a scalable, multi-tenant, multi-platform, multi-network, and global. This could be as simple as your web based email service or as complex as a globally distributed load balanced content delivery environment.

I think drawing a distinction on whether its, PaaS, SaaS, HaaS is completely secondary, ultimately all these approaches are attempting to solve the same problems (scale). As software transitions from a traditional desktop deployment model to that of a network & data centric one, "the cloud" will be the key way in which you develop, deploy and manage applications in this new computing paradigm."
- Reuven Cohen

"I view cloud computing as a broad array of web-based services aimed at allowing users to obtain a wide range of functional capabilities on a 'pay-as-you-go' basis that previously required tremendous hardware/software investments and professional skills to acquire. Cloud computing is the realization of the earlier ideals of utility computing without the technical complexities or complicated deployment worries."
- Jeff Kaplan

"People are coming to grips with Virtualization and how it reshapes IT, creates service and software based models, and in many ways changes a lot of the physical layer we are used to. Clouds will be the next transformation over the next several years, building off of the software models that virtualization enabled."
- Douglas Gourlay

"The way I understand it, “cloud computing” refers to the bigger picture…basically the broad concept of using the internet to allow people to access technology-enabled services. According to Gartner, those services must be 'massively scalable' to qualify as true 'cloud computing'. So according to that definition, every time I log into Facebook, or search for flights online, I am taking advantage of cloud computing."
- Praising Gaw



See next page for definitions from Damon Edwards, Brian de Haaff, Kirill Sheynkman, Ben Kepes, Omar Sultan, Kevin Hartig, and Yan Pritzker

See final page for for definitions from Trevor Doerksen, Thorsten von Eicken, Paul Wallis, Michael Sheehan, Don Dodge, Aaron Ricadela, Bill Martin, Ben Kepes and Irving Wladwasky Berger.