In a previous post, “What The Heck Is Cloud Computing?” I broke the cloud up into three categories.  however I do not think I did a good job of delineating these categories with examples.  So here goes:

IaaS: Infrastructure as a Service  

PaaS: Platform as a Service

SaaS: Software as a Service

 

And thanks to a heads-up from Dare Obasanjo, I found a somewhat different labeling of the cloud from Tim O'Reilly in his blog post Web 2.0 and Cloud Computing.  His breakdown is:cloud.jpg

Utility computing

  • “…virtual machine instances, storage, and computation at pay-as-you-go utility pricing…”

Platform as a Service

  • “…which hide machine instances behind higher-level APIs”

Cloud-based end-user applications

  • “Any web application is a cloud application in the sense that it resides in the cloud. Google, Amazon, Facebook, twitter, flickr, and virtually every other Web 2.0 application is a cloud application in this sense. However, it seems to me that people use the term "cloud" more specifically in describing web applications that were formerly delivered locally on a PC, like spreadsheets, word processing, databases, and even email”

where these labels pretty much correspond 1 to 1 to the ones above.

I hope this clarifies things a bit.

This is part 2 of a series:

  1. What The Heck Is Cloud Computing?
  2. <this post>
  3. What The Heck Is Cloud Computing? – Another re-look, with Pretty Pictures