PaaS cloud computing platform is a developer programming platform which is created for the programmer to develop, test, run and manage the applications.

A developer is able to write the application as well as deploy it directly into this layer easily.

PaaS allows you to create applications using software components that are built into the PaaS (middleware). Applications using PaaS inherit cloud characteristic such as scalability, high-availability, multi-tenancy, SaaS enablement, and more

PaaS extend and abstract the IaaS layer by removing the hassle of managing the individual virtual machine.

In PaaS cloud computing platform, back end scalability is handled by the cloud service provider and the end user does not have to worry about to manage the infrastructure.

PaaS services are hosted in the cloud and accessed by users simply via their web browser.

All the infrastructure to run the applications will be over the internet.

Apprenda is one provider of a private cloud PaaS for .NET and Java.

PaaS providers provide the Programming languages, Application frameworks, Databases, and Other tools:

1. Programming languages

PaaS providers provide various programming languages for the developers to develop the applications. Some popular programming languages provided by PaaS providers are Java, PHP, Ruby, Perl, and Go.

2. Application frameworks

PaaS providers provide application frameworks to easily understand the application development. Some popular application frameworks provided by PaaS providers are Node.js, Drupal, Joomla, WordPress, Spring, Play, Rack, and Zend.

3. Databases

PaaS providers provide various databases such as ClearDB, PostgreSQL, MongoDB, and Redis to communicate with the applications.

4. Other tools

PaaS providers provide various other tools that are required to develop, test, and deploy the applications.

Popular PaaS Providers

The below table shows some popular PaaS providers and services that are provided by them –

Advantages of PaaS cloud computing layer

1) Simplified Development:-Developers can focus on development and innovation without worrying about the infrastructure.

2) Lower risk: No requirements of up-front investment in hardware and software. Developers only need a PC and an internet connection to start building applications.

3) Prebuilt business functionality: – Some PaaS vendors also provide already defined business functionality so that users can avoid building everything from very scratch and hence can directly start the projects only.

4) Instant community:- PaaS vendors frequently provides online communities where developer can get the ideas, share experiences and seek advice from others.

5) Scalability: – Applications deployed can scale from one to thousands of users without any changes to the applications.

Disadvantages of PaaS cloud computing layer:-

1) Vendor lock-in:– One have to write the applications according to the platform provided by PaaS vendor so migration of an application to another PaaS vendor would be a problem.

2) Data Privacy:- Corporate data, whether it can be critical or not, will be private so if it is not located within the walls of the company there can be a risk in terms of privacy of data.

1. Infrastructure as a Service (IaaS)
2. Platform as a Service (PaaS)
3. Software as a Service (SaaS)
4. Identity as a service (IDaaS)
5. Network as a service (NaaS)

Infrastructure as a Service (IaaS)

IaaS is also known as Hardware as a Service (HaaS). It is a computing infrastructure managed over the internet. The main advantage of using IaaS is that it helps users to avoid the cost and complexity of purchasing and managing the physical servers.

Characteristics of IaaS

There are the following characteristics of IaaS –

• Resources are available as a service
• Services are highly scalable
• Dynamic and flexible
• GUI and API-based access
• Automated administrative tasks

Example: DigitalOcean, Linode, Amazon Web Services (AWS), Microsoft Azure, Google Compute Engine (GCE), Rackspace, and Cisco Metacloud.

Platform as a Service (PaaS)

PaaS cloud computing platform is created for the programmer to develop, test, run, and manage the applications.

Characteristics of PaaS

There are the following characteristics of PaaS –

• Accessible to various users via the same development application.
• Integrates with web services and databases.
• Builds on virtualization technology, so resources can easily be scaled up or down as per the organization’s need.
• Support multiple languages and frameworks.
• Provides an ability to “Auto-scale“.

Example: AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos, Magento Commerce Cloud, and OpenShift.

Software as a Service (SaaS)

SaaS is also known as “on-demand software“. It is a software in which the applications are hosted by a cloud service provider. Users can access these applications with the help of internet connection and web browser.

Characteristics of SaaS

There are the following characteristics of SaaS –

• Managed from a central location
• Hosted on a remote server
• Accessible over the internet
• Users are not responsible for hardware and software updates. Updates are applied automatically.
• The services are purchased on the pay-as-per-use basis

Example: BigCommerce, Google Apps, Salesforce, Dropbox, ZenDesk, Cisco WebEx, ZenDesk, Slack, and GoToMeeting.

Difference between IaaS, PaaS, and SaaS

The below table shows the difference between IaaS, PaaS, and SaaS –