3 service models.
(Cloud Software as a Service (SaaS)
Cloud Platform as a Service (PaaS)
Cloud Infrastructure as a Service (IaaS)
Cloud Software as a Service (SaaS) :
Software as a service (SaaS) is some time called as on-demand software. But if we go through the definition, it will be the licensing delivery model in which service provider uses subscription basis services. It means, the software will be hosted centrally and the customer uses that software through low-cost computing devices like a thin client and can access it by browsers. Now a day most of the company migrating towards the software as a service because of it high reliability and low maintenance cost. The most famous category of this services are, CRM, MIS and CRM type of software.
Benefit of the model :
Once you subscribe the SaaS services then you will get the latest services of the IT.That means, you don’t need to update the software with newly arrived patches, also there is no need to bother about the security issue of the same.Because once the copy of your software is updated by the cloud server then you will get the updated one. The most useful thing of this model is, No need to bother about the upgrading of the hardware to drive the latest software on it. Nowadays we also have cloud antivirus, which uses the processing power of server and not your local machine. The biggest driving force behind the cloud computing industries is its cost-reducing policy by outsourced hardware, maintenance, and support.
Cloud Platform as a Service (PaaS) :
If you are the web app developer and still working on the stand alone machine then this service is best for you. If you want to develop a CRM application then PaaS is best for you. Now, what is this PaaS stands for? Okay ! it’s a Platform as a service but which platform it is.
E.g: Suppose you want to start a small firm for web app development, now the first thing you need to consider is, purchasing latest computer, then you need to install the platform for development and frequently need to update with new packages or patches to keep it updated…Now consider you are subscribing the PaaS then you will able to do the same thing with the help of low-cost computing device and also there is no need to install the development platform on your local stand alone machine. You just need to login to the server and start the development and you can deploy your developed app on the internet and also can sell it on the online market. The best example of Paas is salesforce.com which is the biggest CRM cloud which I know.
Cloud Infrastructure as a Service (IaaS) :
In the above example, we consider the scenario of small firm and its development environment. Now consider, the same firm is dealing with the huge customer data and backup of the same data. Then you need to upgrade your storing capacity as per the demand of the customer grows and you also need to bother about the backup of the customer data in case of any disaster. and if we consider the maintenance cost of the RAID then it will be costlier. But if you subscribe the IaaS then everything will go well and your storage capacity will increase as per the demand and no need to pay only for the uses, that mean no need to stock the resource for the future.