Cloud computing did not come about overnight; it is a logical continuation of changes that have been taking place in the background for many years. It is not a panacea but at its best it frees organisations from the need to worry about information technology and allows them to focus on using automation to support more flexible and efficient business operations. It is a useful adjunct to the Rapid Incremental Development described previously.
As a starting point the most widely used definition is that from the National Institute for Standards and Technology in the USA. It is the definition used by the US and UK government amongst others.
"Cloud computing is a model for enabling 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. This cloud model is composed of five essential characteristics, three service models, and four deployment models. “
To interpret it more simply; cloud computing is about providing all or part of an organisation’s computer systems quickly, flexibly and largely automatically. In its purest form cloud computing is an on demand service, like a utility, where the consuming organisation only pays for usage.
As so often happens computer service suppliers with a vested interest in older technology rebadge their technology as though it was built for the new direction. This has been the case with cloud computing; indeed it is such a recognised abuse of the term it has even got its own name “cloudwashing”; old products that are repackaged and relabelled with cloud reference which are really old data centre based offerings, sometimes with a modified pricing model. So the buyer of cloud services needs to understood the key aspects of “the cloud” and cloud services.
NIST identifies five main characteristics and they provide a good starting point for understanding the nature of cloud services and avoid “cloudwashed” offerings. In summary the main features of an idealised cloud service are:
The more closely a service matches the above characteristics the more properly it can be called a cloud service. In future articles we will consider the other key aspects, the three service and the four broad deployment models, to complete the description of true cloud services.