What is the difference between Data Center and Cloud Computing ?

It’s getting more confusing with the term virtualization.

The blog from thecloudguytim describe the difference between (private) cloud and data center with this statement.

A private cloud is any cloud you operate that can only be accessed by persons with the proper security authorization.

A cloud can be hosted on your own computers or on the computers that are located some place else.

A data center, on the other hand, is a physical location where your computing hardware components are located. A data center consists of all the computers and hardware at one location. They can be owned by the same person or a variety of persons. They may be managed by one person or company and owned by another.

The data center computers could host a single private cloud, several private clouds, a few private and a few public clouds or all public clouds. In a word, the data center is the hardware on which your clouds are hosted.

Quite understandable, that Data center related to infrastructure location that managed by data center provider, meanwhile a cloud is a service that can be accessed from some place else, either privately or public.

Another term for portfolio business is IT Managed Service, that could be almost the same in certain aspect with data center.

But still, if they differentiate with hardware and service. The term of IaaS as part of Cloud computing that represent Infrastructure as a Service could be done by Data Center as well (physically).

So if one firm provide portfolio Cloud and Data Center, the physical infrastructure might be the same. The difference is on business model, pricing transaction, and perspective of Physical hardware or Service (even for infrastructure).

And what about virtualization ? …. (for me,  it is just a concept that tells about the same thing, lets check it out)