What are the various cloud computing models? To sort out some of the confusion around cloud computing, it is helpful to understand the various cloud service models, of which there are three – software as a service (SaaS), platform as a service (PaaS) and infrastructure as a service (IaaS). next
SaaS is the most widely known flavour of cloud service. SaaS is sometimes referred to as on demand software. With SaaS, software and its associated data are centrally hosted and are typically accessed over the internet using a browser. What are some examples of SaaS? MailChimp, the application we use to distribute our newsletters, is an example. Google Apps is another example as is Dropbox, and the list continues to expand.
PaaS provides the delivery of a computing platform and required solutions to facilitate the deployment of applications without having to invest in the cost and complexity of hardware and software. Some examples of PaaS include Microsoft Azure and Google’s App Engine.
The IaaS service model allows clients to avoid the procurement of servers, software, data centre space and network equipment. Such resources are provided as a fully outsourced service. Examples of IaaS include Amazon’s Elastic Compute Cloud and Rackspace.
In addition to the various cloud service models, it’s useful to understand the delivery models through which cloud computing is distributed. The main delivery models include public, private, community and hybrid.
A public cloud offers infrastructure and solutions to the general public and is typically owned by a large organization that sells cloud services. A private cloud is designed solely for one organization. A private cloud may be managed by the organization which uses it, or by a third party, and the infrastructure may be located on the site of the cloud user or elsewhere.
A community cloud is shared by several organizations and supports a community of users, usually with some common interest, such as regulatory concerns. A hybrid cloud model consists of two or more clouds, for example a public and private cloud, bound together by technology to facilitate data sharing and portability. Egnyte, a file storing and sharing service, is an example of a hybrid cloud computing solution.