Cloud basically means a network and anything that is connected to a single network and can be accessed from anywhere can be considered as Cloud.

All that we see on the internet through the browsers, is not stored in our computer. We can merely access, and view the data as and when required. Similarly, cloud application services are like having our entire computing power on the internet, which can be made available to us as and when required, and in whichever amount.

Consider an example of a company having 500 employees, and each of them using a computer of 8 GB RAM, with a dual-core processor of 2.4 GHz, and 256 GB hard drive. Now, not each and every employee requires this much computing power. Like a content writer would not require as much processing as a Java developer. And supposedly, for an emergency big scale project, the company needs 200 new and temporary developers for 6 months. So, it will have to invest in additional computers which will be free within 6 months.

Here, the company can use the Cloud Application service as a sigh of relief. Thus, each employee will use only the required amount of computing power from the server. New employees can plug into the server for 6 months and use as much of the service required. The company will have to pay ONLY for the service used. This is the power of the Cloud.

Today, industries and companies are turning to be 100% cloud-based by developing a cloud app, instead of developing a native mobile app and website separately. According to International Data Corporation, companies spending on Cloud Application Service are going to hike 6 times in accordance with the current IT trends. The Cloud Market has seen a growth of 21% in the last year and is expecting to see a rise of 17% in 2019. By 2020, more than 60% of IT infrastructure, technologies, software, and services will be Cloud Based. Businesses today are getting highly influenced by cloud application service as it is incorporating with new technologies like (IOT) Internet of Things, DevOps, BigData, etc.

There are countless articles and literature available on the topic of Cloud available on the internet. But it becomes very difficult to understand those articles without knowing the basic terminologies of cloud computing. So in this article, I will explain the most important and common concept of cloud service models in the easiest way possible.

What is Cloud Services?

Just another IT service like database management or network security, Cloud Application Service is like renting an external resource of computing which can be accessed online through the internet. There is no need for maintaining a large infrastructure when all you need is computers.

This is the same as not owning a farm for vegetable production, rather just buying the vegetables required at regular interval from the vegetable market.

The physical storage network and the environment are owned by companies providing cloud application service. Cloud application service benefits the users by providing easy and scalable access to data, resources, and applications hosted on the cloud. It is an on-demand service so can be molded according to the user's need. Depending on the intention and purpose, there are predefined types of cloud application service.

Infrastructure as a Service (IaaS) — The Bottom Layers of Cloud Infrastructure;

Consider your personal computer on the cloud. Not literally, but think of a virtual computer providing the infrastructure for network storage; hence known as Infrastructure as a Service. The rest has to be managed by the cloud user.

On such a cloud-hosted service, any number of physical machines can operate separately. This means the entire system is partially available which can be operated on the user end system as per customary needs.

Think of a Scenario→ There is a passionate dance enthusiast and he wants to portray his talent to the world. Now, it is not very easy if he starts all by himself.

All the steps included in this will be: To organize a dance show Manage the event Sell tickets Choreograph and Perform.

Now let us understand this simple example by cloud computing reference.

In his pursuit of becoming famous, what if he gets a Sponsorer? The sponsorer will invest and organize his dance show. The dancer thus, need not worry about the expenditure. The dancer, however, will only have to manage his dance show, choreograph his steps and perform. This means that the Sponsor provides an infrastructure to the dancer.

The Role of Stakeholders in Infrastructure as a Service

Let's understand the functioning of this cloud application service. How each stakeholder works with its role.

Cloud Providers

It is the IaaS service providers role to take care of the security, functionality, integration, interoperability, and usability. They maintain the data and the equipment essential for the maintenance. So ideally, they manage networking, storage, servers, and virtualization.

Client/ Company

The clientele of the IaaS has the full command on the infrastructure of the model. They pay a fee for a duration to avail the infrastructure service for as long as they want the service. However, the client companies need to install their own Operating systems, maintain the middleware, take care of the runtime, data and the applications built by them. So, they need to hire IT staff and maintain resources/tools for development.

Software Developers

The developers of the IaaS platform will have access to the data controls and will be provided with resources (tools for development) by the cloud that will be helpful in the development of applications. Their role is to develop and deploy on their platform by integrating the resources themselves. It is like buying all the ingredients for making a cake and then baking it yourself in the oven.

The names of IaaS Service Providers that you must know

The most popular cloud application service provider providing Infrastructure as a Service IaaS is the Amazon Elastic Cloud Compute (EC2) providing hybrid IT architecture, rich controls and auditing, BigData support, backup and storage, disaster recovery and comprehensive security capabilities. It comes in two pricing models, one is the service pricing which goes pay per use above 120 cloud services, and another free tier.

Other IaaS cloud application service providers are IBM SmartCloud, Microsoft Azure, and Rackspace Open Cloud.

Platform as a Service (PaaS) — The Platform for the Developers

A cloud application service model which provides a platform for development through the cloud (internet access) is known as the Platform as a Service (PaaS). It provides self-service portals for the developers for managing computing software from their centralized IT operations.

Platform as a Service can be thought of as a layer above the IaaS. After providing the network and storage infrastructure, it also provides the tools for development, building programs for the developers.

If we consider the dancer's example, PaaS will be like providing a Sponsor as well as an Event Manager for that dancer. So now, he will only have to concentrate on his dance. He will have to choreograph his dance and perform on a pre-developed event stage by the event manager.

The Role of Stakeholders in Platform as a Service (PaaS)

Let us see the role of each stakeholder in the functioning of this cloud application service model.

Cloud Providers

The PaaS providers host the hardware and the software required to build the application on the cloud (internet). The PaaS infrastructure consists of networking, storage, servers, virtualization, Operating System, middleware, and runtime. So along with the infrastructure, PaaS also builds the environment where development can be executed.

Software Developers

The software developers just need to create/develop and run their programs on the cloud interface without having to install the software or maintaining it. They can even launch any number of applications online.

Client Company

The client company, however, has to employ and train its IT staff to learn the development methods online for using a custom platform for a specific development.

The names of PaaS Service Providers that you must know

Customer Relations Management software Salesforce Development is the proof of power depicting Platform as a Service cloud architecture model.

Another good example of PaaS provider is the AWS Elastic Beanstalk for development of Java, .NET, PHP, Python, etc programming language applications.

Yet another PaaS provider is the giant- Google App Engine which not only provides a platform for development but also allows integration of Hadoop, MongoDB, and other upcoming technology trends.

Software as a Service (SaaS) — Redefining User Experience

The Software as a Service (SaaS) comes as a wholesome computing package hosted on the cloud (internet) where the user can access the application interface mostly through a web browser. As this service is delivered online, there is no need for installation or implementations of external applications.

Explaining it with the dancer's example, we now provide him with a Sponsorer, Event Manager as well as a Choreographer. Now, all that the dancer needs to do is- Dance. This will be like a piece of cake for him.

This is an example of SaaS, where event audience can be thought of as the end user and the event management company can be thought of as the cloud application service provider. In return of paying a ticket fee (which can be thought of as the cloud subscription fee), the audience gets entertainment.

The Role of Stakeholders in Software as a Service

Let us see how this cloud architecture model functions and what is the role of each of the participants.

Cloud Providers

The SaaS providers manage everything ranging from networking, storage, servers, virtualization, OSes, middleware, runtime, and data. The companies providing SaaS cloud architecture need to secure large data storage and the platform for development. They are obliged to be responsible for the security of the client's data stored on the cloud.

Software Developers

The developers of the SaaS platform need to build an architecture which will be like an interface between the user and the cloud operations. There won't be need of any installations or downloads. Everything will be accessed online.

End Users

Nothing much will be required by the end users but to enjoy their demanded service without bothering about installation or updatation. In return, they pay for their subscribed service.

The names of Popular Software as a Service that you must know

An instance of SaaS is the Microsoft Office 365 which enables collaboration of office suite with colleagues and customers of a wide range.

How can we forget Google Apps, which is a comprehensive SaaS for productivity tools for n number of users? Other examples of SaaS are Dropbox and Cisco WebEx.

The original article contains some additional points regarding this topic; (link to the article)

• The prediction of growth of each cloud service model (IaaS, SaaS, PaaS)
• The areas in which each cloud service are popular.
• The difference between Cloud native application and Traditional application architecture.

Originally published at https://www.trootech.com on March 5, 2019.