What is Cloud Computing?

Pooled resources... Utility computing... Elasticity... Grid computing... Computing on demand... Software-as-a-service... There is a reason so many experts, in attempting to define Cloud Computing, have resorted to utilizing established technologies within definitions or analogies for this relatively new concept.

The reason is, quite simply, that Cloud Computing is not in fact new – it encompasses a host of existing and well-used technologies. In some ways, it's easier – and more useful – to define what "Cloud Computing" can do to transform your infrastructure and the way your environment delivers applications to users.

Some would argue it's fruitless to define Cloud as an umbrella concept – perhaps that's why so many writers choose instead to define the plethora of cloud-related concepts such as Virtual Cloud, Public Cloud, On-Site Cloud etc. Our early cloud adpoters tell us that what really matters are the needs that are driving you to explore cloud, and what proven and secure solutions are available to address those needs. As with all other technologies, it's about mapping needs to solutions.

At any rate, the first step in understanding how to navigate the host of cloud offerings available today is to adopt a descriptive, working definition for what YOU mean when you say "cloud." Let's start with our own definition.

Univa on Cloud Computing

Cloud Computing (noun): A category of computing solutions where any "Cloud" solution is a technology and/or service that lets users access computing resources on demand (meaning as needed) – whether resources are physical or virtual, dedicated, or shared, and no matter how they are accessed (via a direct connection, LAN, WAN or the Internet).

A Cloud environment must have four basic characteristics:

• Support boundless applications
• Ability to pool resources
• Service based approach to application delivery
• Support for virtualization

Get definitions for key terminology
Have a comment or suggestion? Submit it now »

Behind the Cloud Curtain: The Underlying Technology

Other Resources For Understanding Cloud

OK, that's a start. But where do you go from here? What are those technologies or services that constitute cloud solutions? And are they real or hypothetical?

In working with customers and partners over the past few years, we've discovered a wealth of useful resources online for charting the cloud landscape.

Here are a few of our favorites:

• There's a great video on YouTube by rPath that explains "Cloud in Plain English"
• John Foley @ Infoweek's "Elements of Cloud"
  a list of simple definitions for the parts that make up the whole
• GigaOm has a nice article with several helpful links to still other good sites
• The 5 Characteristics of Cloud, as presented by Dave Malcolm
  (with just enough, not too much, detail)
• Of course, many analysts have produced reports with detailed (and useful) descriptions of cloud computing – here are links to a few that we like (you may need a subscription to access):
  • 451 Group: The Sky's The Limit
  • Gartner: Cloud Computing: Defining and Describing an Emerging Phenomenon
  • IDC's Cloud Blog
    See especially: IT Cloud Services Forecast - 2008, 2012: A Key Driver of New Growth