Virtual Private Data Center
There was a time when the pinnacle of IT infrastructure and pure digital power was a costly data center implementation either on site (something limited only to tremendous enterprise-level businesses), or to hire out to data center installations (still limited to certain business sizes if you wanted anything of measure). Small and medium businesses found themselves unable to really tap this level of technology, and hardware limitations were quite severe.
Cloud computing has changed this. The cloud provides distributed, scalable computing that allows for virtual supercomputer models to be built across scattered yet interlinked servers. This coupled with modern virtualization has given birth to the concept of the virtual private data center.