Cloud Computing: Acronyms (IaaS, PaaS and SaaS) Posted by MOHAMMED ABDUL HAMEED on 12:28 AM

SaaS – Software As A Service

Essentially based on the concept of renting application functionality from a service provider rather than buying, installing and running software yourself. Offerings within this range from services such as Salesforce.com at one end, delivering the equivalent of a complete application suite, to players like MessageLabs at the other, whose services are designed to complement your operational infrastructure.

PaaS – Platform As A Service

Platform as a service (PaaS), which is all about providing, a platform in the cloud, upon which applications can be developed and executed. Players like Google, again Salesforce.com (this time with Force.com), and Microsoft (with Azure) exist in this space. Facilities provided include things like database management, security, workflow management, application serving, and so on.

IaaS – Infrastructure As A Service

Infrastructure as a service (IaaS). The proposition here is the offering of compute power and storage space on demand.

The difference between this and the other two categories of cloud is that the software that executes is essentially yours. In practical terms, the model is based on the same principles of virtualisation that we are all familiar with in the context of server partitioning or flexible storage. Rather than running a virtual image on a partition existing on a physical server in your data centre, you spin it up on a virtual machine that you have created in the cloud. Virtual disks can be created in a similar manner, to deal with the storage side of things.