Cloud (computing) – What is it ?

Amazon, Google, and now Apple are offering services for music storage on the “cloud.”  For a non-IT person what does “cloud” mean in Apple’s “iCloud” or Amazon’s “music cloud” world? And why is it called “cloud”? To understand that we have to first understand a phenomenon called cloud computing.  The cloud computing story has been gaining strength for more than a couple years in the IT world, but it’s slowly making its way into mainstream discussions only recently.

Cloud computing is a Technical Architecture Model that provides computing capabilities and services from a centralized location. The core idea is that everything is accessed remotely, and you don’t to have anything installed locally.

Cloud computing services can be divided into three categories:

Infrastructure as a Service (IaaS) provides computer hardware, operating systems, databases, file storage, and other raw computing resources. One would say vendors already existed for a long time that provided these resources, so then what’s new? The difference in the cloud computing world is that these resources are provided in a centralized location and maintained by a cloud provider. This means one does not need to have their own data center, and have an infrastructure team to maintain them. That used to be the traditional way of having a hardware and network infrastructure. Some of the IasS providers are Rack Space, Amazon, and Slicehost.

Platform as a Service (PaaS) provides infrastructure that includes both hardware and software platforms that are necessary for software developers to build software. With this, one can build their own software without having to deal with setting up a development environment on their own. An example of this is providing a platform that has an application server like JBoss, a JVM, Linux operating systems, and a database server like Oracle, that are necessary to build software on a Java platform. A few big names in the PasS provider world are Amazon EC2, Go Daddy, and many others. Alternatively, one can create custom software by extending an existing software platform, and by building vertical niches; examples of such providers are SalesForce, Google App Engine, and Microsoft Azure.

Software as a Service is a centralized software distribution model where vendors provide applications that are hosted on their servers, and it can be accessed online by the customers. This is the most commonly known form of cloud computing model that is widely used in day-to-day life. Most common examples of SaaS that we use are Gmail and Google Apps.

Now that we have some understanding of what cloud computing is, you can see that Apple’s iCloud, and Amazon’s Music Cloud basically offer a centralized software solution to manage your music purchases, storage, playlists etc. This falls into the SaaS category. Since “Cloud” is the latest buzz word, hence the inclusion of that word in their products.

Why is it called cloud?

As all the IT people know a cloud is used to depict the network in Technical Architecture diagrams, and since all the services that we mentioned above use the network to access them, the services are said be in the “cloud”.