Cloud services are a matrix with two key dynamics. Firstly, there’s the service model (infrastructure, platform or service). Secondly, there’s the deployment model (public, virtual private or private). Note that a hybrid cloud is a combination of two or more clouds and is merely an amalgam of models, not a model in its own right.
The options, and some well-known public cloud examples, are shown in the table below.
|IaaS||PaaS||SaaS||Tenancy & Access|
|Public Cloud||Publicly accessible shared compute & storage resources, e.g. Amazon Web Services||Publicly accessible shared aap or web development platform, e.g. Microsoft Azure or force.com||Publicly accessible shared software e.g. Google Docs||Multi-tenant Internet access, password protection only|
|Virtual Private Cloud||Secure shared compute and storage resources||Secure shared development platform||Hosted email, CRM, etc, shared software environment||Multi-tenant private network or Internet VPN access|
|Private Cloud||Secure dedicated compute and storage resources||Customer-specific dedicated development platform||Hosting of customerspecific dedicated software environment||Single-tenant, private network or internet VPN access|
The matrix also describes if the service is multi-tenant (shared, multiple customers) or single-tenant (dedicated to one customer) and how it is accessed, as it is the desirability of these features that often determine the deployment model selected.
“Up to the Cloud” has been brought to you to explain what these options are, the pros and the cons, to help you to understand which works best for you. There’s no right or wrong answer, just different scenarios. Typically, the first decision is based along service model (e.g. are you looking for just compute and storage or full software/application provision) before deciding on the deployment model (often with tenancy and access options being the determinant). Separate pages will describe all these services and models in details, busting some myths along the way, to provide you with a Plain English, straightforward view of the options.