As discussed in my previous blog about basics understanding of cloud, Cloud computing is a technology model in which a vendor provides hosted services to users over the internet.

Based on your requirement, you may decide upto which layer you need access and control. Vendor may manage lower layers for you while you just focus on your priorities.

These standard service models actually gives you an idea, from which layer you will have access or control.

The services they offers has been divided mainly into three different models – IaaS, PaaS & SaaS

  1. IaaS (Infrastructure as a Service)

In this service, the Cloud Service Provider provides the customer with virtual machines and other resources as a service. Customer can access the Virtual machine, hence has control over the operating system and above layers. These VMs are created over some physical machine at service provider’s datacenter, but you neither have access to it nor knowledge about it’s where-about. If the user wants a Linux machine, he gets a linux machine, he will not worry about the physical machine or the networking of the system on which the OS is installed.

Example : AWS(Amazon Web Services) provides IaaS service product like AWS EC2.

  1. PaaS (Platform as a Service)

PaaS is a model in which a service provider (here, not necessarily cloud service provider, some other vendor may offer the service using some cloud infra in backgroud) hosts an application development platform on its own infrastructure and makes that platform available to users over the internet. You just manage your application, and not worried about the underlying environment setup including Runtime, Middleware, Operating system or even VM. You just manage your application and your data.

Example : Google App Engine, offered by GCP. You just upload your application to run it.


  1. SaaS (Software as a Service)

SaaS is a model in which a service provider hosts applications on its infrastructure and makes them available to users over a network, typically the internet. You just use the application. You are neither worried about application environment, Infrastructure or even application development. Doesn’t that makes life easy :). It depends again what level or control is desirable.

Example : Google gmail, you use this application for your mails and don’t have access to application or underlying infrastructure.


You have maximum access and control in IaaS model, and minimum in SaaS model. So the cloud service model selection decision depends of level of access/control you need and/or what all you want to outsource for the certain level of management to service provider. Please note that although the service model for you, as a consumer, may be SaaS, where you are just using the application, but there is some vendor who is actually managing the underlying infrastructure components for you.

Hope this blog helps you with the understanding of standard cloud service models.

We will be discussing cloud deployment models of cloud in my next blog.

Please do share your comments and suggestions.


12+ Year IT professional SME with expertise in Middleware, Cloud Computing & DevOps Methodology.

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