Overview

IaaS

It's pay-as-you-go service where a third party provides you with infrastructure services, like storage and virtualization, as you need them, via a cloud, through the internet.

As the user, you are responsible for the operating system and any data, applications, middleware, and runtimes, but a provider gives you access to, and management of, the network, servers, virtualization, and storage you need.

You don’t have to maintain or update your own on-site datacenter because the provider does it for you. Instead, you access and control the infrastructure via an application programming interface (API) or dashboard.

IaaS gives you flexibility to purchase only the components you need and scale them up or down as needed. There’s low overhead and no maintenance costs, making IaaS a very affordable option.

Public cloud providers such as AWS, Microsoft Azure, and Google Cloud are examples of IaaS.

PaaS

It is where a provider hosts the hardware and software on its own infrastructure and delivers this platform to the user as an integrated solution, solution stack, or service through an internet connection.

Primarily useful for developers and programmers, PaaS allows the user to develop, run, and manage their own apps without having to build and maintain the infrastructure or platform usually associated with the process.

You write the code, build, and manage your apps, but you do it without the headaches of software updates or hardware maintenance. The environment to build and deploy is provided for you.

A few examples of PaaS are AWS Elastic Beanstalk, Heroku, and Red Hat OpenShift.

SaaS

Software-as-a-service (SaaS), also known as cloud application services, is the most comprehensive form of cloud computing services, delivering an entire application that is managed by a provider, via a web browser.

Software updates, bug fixes, and general software maintenance are handled by the provider and the user connects to the app via a dashboard or API. There’s no installation of the software on individual machines and group access to the program is smoother and more reliable.

Dropbox, Salesforce, Google Apps, and Red Hat Insights are some examples of SaaS.