Introduction to Cloud computing in layman terms

Couple of years back, we used to talk about system configuration and offline back. Nowadays, we talk about connectivity to cloud, cloud backup, etc. We also discuss whether a tool is cloud capable or not. What exactly is this cloud? Are we referring to cloud in the sky that helps in providing rain? Or is it something different. We hear new words like virtualization. What is it and how is it different from cloud? Lot of these new terms leaves us confused.

Through this article, I am attempting to decode some of these terms in simple language.

Let's take a huge house as an example. The house is huge, has many rooms and other amenities to accommodate more than 1 family. But as per the norm, only one family stays in the house. Let's say there is a need to accommodate other people than the family staying there. How do we achieve this without causing conflict among those staying there? How do we ensure everyone get to use the amenities without causing any issues between them?

The best option is to appoint a mediator who takes care of ensuring proper splitting of resources and ensuring the required amenities are available for each member staying in the house.

Similarly, if we have a system with lot of resources like CPU, RAM and harddisk and is not being fully utilized, then we can think of converting it into a multiple systems. But we need mediators like in the example above. Hypervisors acts as a mediator which provides an interface to install more than 1 system on 1 physical system. Hypervisor takes care of sharing of resources between multiple systems running simultaneously. This is called Virtualization. Don't get confused with multi-boot. In multi-boot, though multiple OS are installed on a single system, only one OS can be active at a time but in case of virtualization, multiple OS can be active at the same time.

In short, virtualization logically splits a physical system into multiple systems. Resource management i.e. allocation of CPU, RAM and harddisk and other resources are taken care by hypervisor. Vmware, Microsoft Hyper V are a few examples of virtualization software.

Going back to the house example, the mediator can manage sharing of the house among the residents of the house but to interact with them require special language. Only the owners capable of speaking that language could interact with them. It was not easy for everyone to learn that language. To overcome this, an interpreter was appointed who could be the translator between the owner and the mediator. He could understand the language of the owners and convert them into the language the mediator could understand for him to perform his duties.

Similarly, special skills are required to interact with virtualization software. To overcome this, an interpreter layer or automation layer was added on top of it. This automation layer will take input in spoken English language and convert it into instructions a virtualization software can understand. This automation layer is called Cloud software. Vcloud, Openstack are some of the examples of Cloud software. This layer is also called as Orchestration layer ( as in music performance, an orchestrator who is also called the conductor controls how the different musicians play their instruments. Similarly, here the cloud software controls how virtualization software works).

Summarizing, virtualization is used to effectively utilize system resources by enabling to run multiple systems on a single physical system while cloud software provides an automation layer to automate system deployment in virtualization environment.