What is the difference between IaaS, PaaS and SaaS?

IaaS, PaaS and SaaS are 3 different forms of cloud computing delivery model to provide services over wide area network (WAN) to the consumer.

IaaS provides on-demand quick provisioning of virtualized hardware infrastructure resources such as server, storage and network.

PaaS provides on-demand quick provisioning of platform software or middleware execution environment such as message queue, relational database management systems and container orchestration systems.

SaaS provides application or software services through web to the consumer. SaaS does not require consumer managing underlying platform and infrastructure. Email service, data backup service and SMS service are example of SaaS.

How to Choose Between IaaS, PaaS and SaaS?

Choose IaaS:

• When you need flexibility of controlling virtualized hardware
• When you need to control the operating system of application

Choose PaaS:

• When you are not going to install platform software or middleware and underlying operating system
• When you are not going to manage and maintain underlying middleware and operating system

Choose SaaS:

• When you need to have a ready-to-use application or software without managing the underlying stack