That's obviously no simple question, but here's a quick video that gives some of IBM's answers:
This is from IBM's Cloud Computing pages. You can access the original RC2 video from Why use IBM for cloud computing?
Like the video says, cloud computing is not:
- Grid computing
- Utility computing
- (I would add service-oriented architecture)
Those are part of it, but cloud computing is more. According to IBM:
Cloud computing is a service management platform that provides a transparent infrastructure to users with near zero management costs.
The video then goes on to talk about our Research Compute Cloud (RC2). See "IBM Advances Research through Cloud Computing to Help Solve Real-World Problems."
In Irving Wladawsky-Berger discusses cloud computing with Tech Web TV (which I wish IBM would put on YouTube), one of IBM's leading thinkers describes these advantages of cloud computing:
- The availability of huge numbers of business and consumer services.
- The ability to deliver such services with tremendous quality.
- The promise of making the experience for the users much better than it is today.
Another great quote is, "People don't want software-as-a-service, they want services."
He discusses this further in "Reflections on Cloud Computing," "The Promise and Reality of Cloud Computing," and "What is Cloud Computing, Anyway?" (all on his self-titled blog).
One point he makes in another interview is that cloud computing is basically "an Internet of services":
Thanks to my collegue Byron Pojol for pointing out the RC2 video.
Also, check out Intro to Cloud Computing, which a reader was kind enough to describe as "one of the best introduction about cloud computing and grid computing."