Cloud Computing is an extension of the term “Software as a Service” (SaaS).  It has become popular as of late due to the extensive promotion by Salesorce.com.   What is now “Cloud Computing” used to be called SaaS (Software as a Service), a definition that actually described what it was quite nicely.  Now we have this nebulous term – Cloud Computing.   The Wikipedia definition is below and it adequately explains what Cloud Computing is.

Cloud computing is Internet-based computing, whereby shared resources, software and information are used by computers and other devices on-demand, like a traditional utility.

Although there is still a blurred line between what Cloud Computing providers offer and traditional web hosts,  the concept of a “cloud” was similar to the CDN.  CDN’s which deliver conent from a vast distributed network of servers, pick the faster route to the consumer of content.  They are generally the closest.  Cloud computing was originally coined with the same thought in mnd, except instead of content, it was applications.  Where you might have a world-wide audience, application instances would be geographically distributed.   Geo distribution is not the only differentiator from a “hosted application”.  The cloud will also grow elastically.  As in a CDN servers are not dedicated to a specific customer.  The same is true in the cloud as long as we are not talking company proprietary.   VM’s can expand and contract based upon demand. 

In my opinion, Salesforce.com does take liberties when they claim to own “Cloud Computing”.  Their SaaS solution does not fit the “cloud” model described above.   But hey, “cloud computing” sounds so much cooler than SaaS, I can’t blame them for taking liberties.