Cloud computing for layman

Before digging to the concept of cloud computing, Let's see how we consume electricity. Basically in every region some companies/organisations are providing electricity to every house. Electricity provider uses Copper or Aluminium wire to provide eletricity to our houses. In addition to that, external electric meter is attached in every house to monitor the amount of electric power we are consuming.

Now imagine computer instead of electricity. Some organization may offer you computers instead of electricity. Computers will be rented to you over high speed internet by some organization. The computers are not provided physically by shifting the machines to your location, rather, the organizations/providers allow you to connect to that computer over high speed internet. A large number of computers are used by the provider. Those large number of computers, also known as servers, are kept in secure place called Data Center. Henceforth, we will use the term server instead of computer. The organization is called cloud service provider (CSP) and the users are called cloud user. So here we have two entities: cloud consumer/user, and the CSP.

The CSP also provide the software on a rented instead of the server. Let’s say, I want to use MS office. In that case I’ll have two options: either buy the software or rent from the CSP. In later option, you will be allowed to access the software through a webpage or some explicitly designed different interface. Such interface will provide you all the required functionalities and you need to pay based on different costing model. This kind of service offered by the CSP is called Software as a Service (SaaS). For example, Google Apps, Salesforce etc

User may also request the CSP multiple number of servers with certain configuration. For example, One may ask the CSP to provide two servers with 4GB memory, 50GB storage, 4 processing units. Offering such service to the cloud users is called Infrastructure as a Service (IaaS). For example Amazon AWS, Windows Azure, Google Compute Engine, IBM SmartCloud Enterprise, Rackspace Open Cloud etc.

Coming to another type of service, CSP also customize the service based on the users requirement such as providing the platform. Here user refers to the software developer. CSP provides all the required software components, such as database servers, programming environment etc, in order to develop a software tool. Such kind of service is called Platform as a Service, in short PaaS. For example, Google App Engine provides the environment to develop web applications using Java, Python, PHP and Go.

Fig. 1 : Snap of data center’s inside view [src]

Thats all about the basics of Cloud Computing. Next, we will see the underlined technology behind the cloud computing.

-Thank you