...a fuzzy term like "love" or "happiness" that nobody seems to be able to describe. I'm pretty sure that it got its name from the typically used graphic that represents the Internet in network designs (a cloud).

So, what makes up a cloud? Let's outline what makes up some other computing environments first.

- Application running on an operating system running directly on a physical server, all located at the place of use (in house).

- Application running on an operating system running as a virtual machine on a virtual machine monitor running on a physical machine, located in house.

- Distributed applications running on several operating systems, each running directly on a physical server, located in house.

- Distributed applications running on several operating systems, each running as a virtual machine on a virtual machine monitor running on a physical machine, located in house.

- Applications running on operating systems running as virtual machines on several virtual machine monitors running on several physical machines (not necessarily one VMM per physical machine), located in house.

Add "not located in house" to any of the above and you have a hosted service. That's nothing new. This blog is a hosted service.

Find a way to charge users only for the time needed for processing and you have utility computing. This blog wouldn't be utility computing, but using network.com (it used to be there--maybe it'll come back) for the rendering of 3D animated movies and paying only for the processor time would be.

The phrase "Computing in the cloud," as used by many people these days, is a very broad generalization that includes hosted services (not located in house), utility computing (pay only for what you use), and virtualization with both to simplify the deployment and management of services and compute nodes. Cloud Computing needs to be vague and generic for the term to be useful, but it's such a challenge trying to decipher the real computing environment being referenced as "in the cloud."