Before you run away screaming, don't worry: let me assure you I do not plan to offer yet another definition of "cloud computing" to join all those hundreds of other divergent definitions running around out there.
But I will point you to
Dave Linthicum's and
Joe McKendrick's musings on the subject.
They both cite the current NIST definition of the term:
“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.”
Which is not the worst definition I have heard today. But then both Dave and Joe argue that it doesn't go far enough. I'm not sure how Dave squares that with his earlier assertion that "extensive overuse and misuse" have rendered the phrase nearly meaningless... it seems to me that "overuse and misuse" are just a result of other folks broadening the definition in ways that he does not approve. He goes on to say:
The concept of cloud computing is about the ability for organizations to stop solving all IT problems by themselves. It's certainly about sharing resources, such as storage and compute services, but it really should be more about sharing solutions and pushing risk out of the business.
Really? Outsourcing is now also "cloud computing?"
I tend to agree with Joe when he says "Ultimately, the term may disappear, vendors will move on to hyping the next big thing, and we’ll remove the “cloud” from “cloud computing” as it simply becomes a ubiquitous method by which applications and services are assembled and accessed." The hype, however, is coming as much from these columnists as vendors, and all seem equally culpable in my view of distorting and diluting the term.
Which is why I will continue to avoid using it inasmuch as is possible.