It had to happen. Just having “the Cloud” was too simple. In the same way that the Internet morphed into intranets, extranets and more, cloud computing is now branching out into internal, external, inter-, public and private clouds. Vendors and service providers alike have seen the opportunity to leverage existing solutions and create their own niches within the overall cloud environment. To help you see the individual silver linings for your disaster recovery plan, here is a quick guide to cloud terminology.
Public Cloud. Basically what the cloud started as: service providers offering IT resources over the Internet with various levels of service and performance. A big advantage is the scalability of investment from a few dollars per month to as much as you can pay for. Possible concerns are in the robustness of the provider and network security.
Private Cloud. Your own cloud, built on your servers and software on your premises (but see “Internal Cloud” below). Although you can have a cloud between servers in the same computer room, risk can be reduced by having a cloud spread over several sites. Does this look like IT virtualisation? It should do – to fulfil promises of flexible resource allocation and usage-based billing, it uses the same technology.
Virtual Private Cloud. Yes, it’s still your own cloud, but it’s no longer (all) on your premises. When it’s hosted by a cloud services provider, you access it via a virtual private network that nobody else can use.
Intercloud. Connects the cloud spaces of two cloud service providers. For example, Google’s App Engine that connects via APIs to Amazon’s EC2 (“Elastic Compute Cloud”).
Internal Cloud. Another name for private cloud; also referred to as corporate cloud. Just make sure your disaster recovery plan isn’t buying the same solution twice under different names. However, whereas “internal” means physically inside, “private” is now spilling over into the outside as virtual private clouds increase.
External Cloud. An easy one to end with – any cloud service that isn’t internal.