Cloud Computing – Delivery Models

In some of the earlier articles in Technofriends, we learnt about Cloud computing and the security aspects that you need consider while moving in to the cloud. Are you aware that cloud computing is the next Big thing to happen in the Internet related businesses and services?  Due to its flexible model, ease of use and pricing, cloud computing services are gaining popularity among individual users, programmers, small –medium scale enterprises and corporate bodies.

To start with, what is the core model of the cloud computing? It is the SPI model. That is, SaaS (Software as a Service), PaaS (Platform as a Service) and IaaS (Infrastructure as a Service). Learning about these three lingos in detail will give you an insight into this wonderful technology of the next generation, the cloud computing.

SaaS (Software as a Service)

SaaS is the first, widely used successful form of cloud computing as of today. Software as a Service is also well known as ‘Software on Demand’.  This means, based on the user demand, the software is distributed to the users for a pay or Free. The softwares reside in a centralized location in a network (often, the internet or the intranet) and will be available for the users. So, the user need not ‘buy’ the software for a hefty price or even install or upgrade them, but just rent it from a vendor or service provider for a pay. Some vendors offer certain softwares free too. SaaS is widely known because, it reduces the customers’ or users’ overhead of buying, maintaining and scaling up/down any software.

The vendor or the service provider hosts both the software and the data, so the user can use the service from anywhere. Few examples of SaaS are the Google mail, Yahoo mail, Zoho etc.,

PaaS (Platform as a Service)

While the SaaS is well known among the individual users, PaaS is for the software, program or application developers. PaaS gives an development platform for the programmers who write their own code. The PaaS service provider uploads the code written by the developers and presents it on the internet. The developers can write lines and lines of code, test, deploy, host and mainitain applications in this IDE(Integrated Development Environment). PaaS also works on a metering or subscription based pricing where the developers can utilize the chosen platform for as long as they want for a pay. They need not worry about the total complexity involved in setting up the entire platform or maintenance activities like adding patches, upgrades and installations etc.,Few Examples of PaaS are Windows Azure, Wolf Frameworks etc.

IaaS (Infrastructure as a Service)

IaaS is the process of offering the computing infrastructure as a service, like Hardware, storage space, networking components, servers etc.,  Individual users, small-medium businesses, corporate can buy the infrastructure based on their requirements at any time, instead of buying the entire infrastructure that might be used for long.  Like SaaS and PaaS, IaaS too works on the ‘Pay as you Go’ pricing model and wants the users to pay only for what they use.  Few top notch companies like IBM, Amazon, Google offer infrastructure as service. Few examples of IaaS are Amazon Web services EC2, S3 and Rackspace.

What do I choose – SaaS, PaaS or IaaS?

Now that you have an idea about the three main segments of cloud computing, the  SaaS, PaaS and IaaS, you should be focussing on what to avail among the three based on your needs. If you just need an application service, you go for SaaS.  If you are a talented developer or an aspiring one who wants to try your hand at writing code, but do not have the IDE or the required platform, you should look for PaaS. If you have written lines of working code or if you have a software package that you may want to install in the cloud, go for IaaS. With amazing flexibility in services, Cloud computing is born to revolutionize the Information Technology related operations.

Swetha Kalyanee contributed for this article, she is a Freelance Technical Writer(Information Technology) based in Chennai.