Cloud Computing

In the last few years, cloud computing has become the hot button for IT vendors and IT executives. What is cloud computing all about? Cloud computing means obtaining IT capabilities (i.e., hardware, software, or services) from an outside vendor over a network, usually the Internet. “The cloud” is a metaphor for the Internet, so the “cloud computing” phrase means that IT capabilities of some sort are purchased from a vendor and delivered to the customer over the Internet. From the customer’s standpoint, the IT capabilities com from “the cloud” – the customer doesn’t care where the actual computing is taking place. “The cloud is a smart, complex, powerful computing system in the sky that people can just plug into,” according to Web browser pioneer Marc Andreessen.

The details of cloud computing are still evolving, but there are three basic types of cloud computing. Infrastructure as a Service (IaaS) – also called utility computing – provides the computing capabilities (i.e., servers, networks, storage, and systems software) to augment or replace the functions of an entire in-house data center. Such services are offered by traditional vendors such as IBM, Hewlett-Packard, and Sun, as well as companies such as Amazon that possess extensive computing capacity. Platform as a service (PaaS) provides a development environment as a service – virtualized servers on which users can run existing applications or develop new ones. The highest profile examples are Salesforce.com’s force.com, Microsoft’s Azure, and Google’s App Engine. Software as Service (Saa) is the most widely known and widely used form of cloud computing.  SaaS delivers a single application to its multiple users through a Web browser. Familiar examples include Google Gmail and Apps, VoIP from Vonage and Skype, and IM from AOL, Yahoo!, and Google. The key to these types of cloud computing, and to the many variations that exist, is that computing capabilities of some sort are being delivered to the user via a network, usually the Internet.

Note that while the cloud computing terminology is relatively new, the underlying concepts are decades old. Utility computing in some form has been offered for more than two decades. Application service providers (ASPs) arose in the 1990s, where the customer elected to use a “hosted” application – running on the ASP’s server –rather than purchasing the software application and running it on its own equipment. SaaS has also been around since the 1990s. However, the range of cloud computing services now available – or at least currently under development – is making cloud computing a much more attractive alternative for IT executives who need to be able to increase capacity or add capabilities quickly, without investing in new infrastructure, personnel, or software. Cloud computing, in some form, appears here to stay.