What is Cloud Computing?
The most important thing you need to know about cloud computing is that it’s just a bunch of computing resources which you can provision depending to your needs. These resources include servers, storage and applications, and the required network connectivity for accessibility.
By Howard Young
There are three aspects to cloud computing which I will explain in this short definition of the term. Basically you have to understand that cloud computing has been around in one form or another since the internet was developed — and perhaps earlier than that if you consider computer time shares – and has evolved into a utility model where the resources are leased to the users.
I suggest that you categorize this model into three major components known as the infrastructure, platform and software, even though the later two are probably one in the same, where these components are leased as a service to the user and are commonly named Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). For a more in depth technological description, please check out this document on the cloud computing architecture.
The infrastructure is very capital intensive requiring a large investment to build out a data center where the servers and storage reside. Companies such as Amazon and Google having spare resources decided that it was possible to lease out the unused capacity to users for a nominal or metered rate.
Platform services have two things in common regardless of who the supplier is. That is, all platform services provide an interface for the user to access the application and the platform provides the structure with the application runs.
Goggle’s AppEngine is the most recognizable PaaS where it provides a development platform for Python and Java apps. The AppEngine hides the infrastructure from the developer allowing them to build the app instead both the platform and app.
The software as a service model in cloud computing can be applied to just about any desktop or server application. In this model, the developer produces an app and leases the use of the application to the user on a monthly or annual basis. Here the user benefits by having access to the software from an independent platform through a web browser. However, the application and data is not accessible if the network connection is offline.