From a user's point of view, a good cloud computing definition is using Web applications and/or server services that you pay to access rather than software or hardware that you buy and install.
According to "What Cloud Computing Really Means" (Galen Gruman and Eric Knorr, InfoWorld, April 07, 2008), cloud computing can include everything from SaaS (Software as a Service providers) through development environment services (building applications on the service provider's infrastructure which can then be delivered to users over the Internet.)
So my business might use cloud computing to access online accounting and payroll services, rather than investing in accounting and/or payroll software myself.
Besides being the next big IT thing, cloud computing offers obvious advantages for businesses of all sizes. The huge advantage is that you don't need the infrastructure or the knowledge necessary to develop or maintain the infrastructure; someone else is taking care of all that. Cloud computing also lets you:
- access a broad range of applications, services, and hardware that you might not be able to access otherwise
- cut costs by "renting" software and applications rather than paying to have software and applications installed on your own equipment - which you may also have to buy or upgrade
- save time by not having to install and or upgrade software and applications
- access applications specific to your business needs that are only available over the Internet
Downsides to cloud computing include the difficulty of managing cloud computing and the legal and business risks to using cloud computing, such as the problem of downtime and data security. Bernard Golden discusses these and other issues in "The Case Against Cloud Computing"(CIO.com).
Why cloud computing? Cloud is a metaphor for the Internet. Plus it's just a catchy name.
