Cloud computing architecture type?

what kind of architecture model the internet is based on? is that three-tier, n-tier? please tell me.Cloud computing architecture type?
There's a difference between the Internet and Cloud Computing.



The Internet is a network of networks, and is as such potentially n-tier.Cloud computing architecture type?
Architecture of a cloud service will depends on the model used. Cloud Computing Service are offered through following models (SPI Model):

--SaaS (Software as a Service) %26gt; for consumers.
--PaaS (Platform as a Service) %26gt; for app. developers
--IaaS (Infrastructure as a Service) %26gt; any one who needs complete control.

You can read more about a simple introduction of Cloud SPI model here:

http://www.techno-pulse.com/2011/06/clou…Cloud computing architecture type?
In general, the essence of cloud computing is the way of keeping information. In traditional computing, we store all data and programs on our PCs and normally we can access them only through the same computer unless you allow remote access. Whereas in cloud computing all necessary data and programs are stored in the service provider’s information centre and thereof they can be accessed from any PC with an Internet connection. In many cases you don’t even have to download and install any applications to your computer, because they are already in the “cloud”. http://deletemalware.blogspot.com/2011/0…