I think in the early days of the commercial Internet, Cloud referred to telecommunications infrastructure that you subscribed to or didn’t know about or care about. Service-orientation is inevitable when technology is applied.. this is because people want service when they have a different focus. Infrastructure-as-a-service (IaaS), Platform-as-a-service (PaaS), and various other technologies-as-services describe somewhat specific cloud architectures and frameworks which can be delivered with participation-in-technical-details-on-demand service level agreements. Cloud Computing (IaaS and arguably PaaS) require automation and self-provisioning to really be actual cloud computing… and there must be a compute service running. Self-provisioning generally is implemented in a way that facilitates IT managers/brokers to delegate provisioning authority to a department or organizational unit. Once the organizational unit can subscribe to the public or private cloud service, they can provision resources on demand and pay (or not pay) for consumed resources. Without automation or self-provisioning… it’s just not cloud computing. It might be some other kind of cloud… like software-as-a-service… but even software-as-a-service requires an autonomy component of some kind. For example, when you use Gmail… you’re using software-as-service. Gmail has automated the delivery of your email. SaaS runs servers in the background and guess what? Servers automate processes. But to really speak with integrity about cloud computing, I think it’s important to know that what we’re talking about is automated, self-provisioning systems that allow people to subscribe to infrastructure-as-a-service on demand. It’s not a puppet show, but more of a vending machine.
There are more characteristics of cloud computing than just automation and autonomy or other methods of self-provisioning. Cloud computing exposes APIs that allow subscribers to access computational resources on demand which serve as an abstraction layer between aggregated (and possibly also distributed) hardware and virtual (or paravirtual) machinery. A proudly provisioned Cloud usually boasts some kind of synergistic automation, monitoring, distribution, and compute aggregation at every service layer. The customer experience should be a burst-friendly, high availability, easy to use, “just-works” success story. Nobody likes when the vending machine takes money then gets jammed or you find out that the people inside your TV and radio are really there looking back at you and listening to all your secrets. So again, the Cloud isn’t a puppet show, but more of a vending machine. Get Served.