Cloud computing has upgraded to a huge extent in recent times, and it has been divided into three major service categories:
- Infrastructure as a Service (IaaS)
- Platform as a Service (PaaS)
- Software as a Service (SaaS)
We will discuss each of these instances in the following sections.
Infrastructure as a Service often provides the infrastructure such as servers, virtual machines, networks, operating system, storage, and much more on a pay-as-you-use basis. IaaS providers offer VM from small to extra-large machines.
The IaaS gives you complete freedom while choosing the instance type as per yourrequirements:
Common cloud vendors providing the IaaS services are:
- Google Cloud Platform
- Amazon Web Services
- IBM
- HP Public Cloud
The PaaS model is similar to IaaS, but it also provides the additional tools such as database management system, business intelligence services, and so on. The following figure illustrates the architecture of the PaaS model:
Cloud platforms providing PaaS services are as follows:
- Windows Azure
- Google App Engine
- Cloud Foundry
- Amazon Web Services
Software as a Service (SaaS) makes the users connect to the products through the internet (or sometimes also help them build in-house as a private cloud solution) on a subscription basis model.
Below image shows the basic architecture of SaaS model.
Some cloud vendors providing SaaS are:
- Google Application
- Salesforce
- Zoho
- Microsoft Office 365
The major differences between these models can be summarized to a table as follows:
Software as a Service (SaaS) | Platform as a Service (PaaS) | Infrastructure as a Service (IaaS) |
Software as a service is a model in which a third-party provider hosts multiple applications and lets customers use them over the internet. SaaS is a very useful pay-as-you-use model.
Examples: Salesforce, NetSuite | This is a model in which a third-party provider application development platform and services built on its own infrastructure. Again these tools are made available to customers over the internet.
Examples: Google App Engine, AWS Lambda | In IaaS, a third-party application provides servers, storage, compute resources, and so on. And then makes it available for customers for their utilization. Customers can use IaaS to build their own PaaS and SaaS service for their customers.
Examples: Google Cloud Compute, Amazon S3 |