Public Cloud vs. Private Cloud: How to Choose

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The biggest question surrounding cloud computing is not whether to adopt it, but which solution to adopt. Between public and private, the answer comes down to your unique business needs.

Cloud computing has been around for about two decades now, buoyed by the “big 3”: Google Cloud Platform, Microsoft Azure, and Amazon Web Services (AWS).

It started as a simple storage solution and then expanded to different dimensions like, but not limited to, platform as a service (PaaS), software as a service (SaaS) and infrastructure as a service (IaaS).

Cloud platforms offer benefits like cost efficiency, security, easy management, scalability and reliability.

The COVID-19 pandemic has accelerated the cloud migration: Many organizations have already shifted to cloud platforms and are enjoying business efficiency and revenue growth. Others are gradually migrating to cloud.

The bottom line? In today's complex business world, digital transformation and cloud migration is the key to success. (Also read: How Digital Transformation Can Bring Resilience During Disruptions.)

What is Public Cloud?

Public cloud can be defined as a cloud infrastructure provided by third-party cloud vendors over the public internet.


The available resources can be anything: computing, virtual machines, software applications, database resources, enterprise infrastructure and many more. Most public cloud providers offer some free resources with limited access and offer the rest of their services on a subscription or pay-per-usage model.

In public cloud solutions, the cloud vendor is responsible for managing the data centers, hardware and software. They provide high-speed network connectivity to ensure smooth functioning and rapid access to the data center.

Essentially, public cloud is a utility model clients can consume over the public internet. (Also read: Optimizing Legacy Enterprise Software Modernization.)

Public cloud platforms are generally multitenant infrastructure. That means multiple tenants, or users, are using virtual resources running on shared physical servers and/or hardware.

These client-specific virtual resources are provisioned through self-service agents. And clients' data is logically separated from each other. In the current global market, the trend is to move some part of computing to the public cloud. Organizations are getting access to readily available and flexible cloud environments almost instantly. The pay-per-usage strategy makes it more attractive while considering client expenditure.

There are several public cloud models available. The most common public cloud service models are:

  • Platform as a service (PaaS). PaaS is for application developers. It provides all the required hardware and software infrastructure for application development.
  • Software as a service (SaaS). This model deals with pre-built software applications hosted in public cloud. You can access these software applications through application programming interface (API) calls.
  • Infrastructure as a service (IaaS). The IaaS model offers access to bare fundamental resources like storage, networking and computing. Within the model, these resources are virtualized and offered to clients.

There are many sub-types of the above models; but they are mainly derived from these fundamental public cloud offerings. Over time many derivatives have been coined: Data as a Service (DaaS), Function as a Service (FaaS), Security as a Service (SeCaaS), and the list goes on.

Advantages and Disadvantages of Public Cloud

The demand for public cloud is increasing everyday. But at the same time, we need to understand that a particular cloud solution always depends on an organization's needs. (Also read: 5 Questions Businesses Should Ask Their Cloud Provider.)

In other words, every cloud solution will have advantages and disadvantages. And understanding those pros and cons can help you choose the right solution. So, let's dive into the advantages and disadvantages of public cloud:

Advantages of Public Cloud

  • Scalability, availability and elasticity. Public cloud is easily scalable to accommodate additional and unexpected traffic.
  • Affordability. You do not need to invest money upfront to accommodate public cloud; you can use pay-per-use model.
  • Reliability. Public cloud platforms are reliable because backup data centers are always there in the event of failure.
  • Ease of maintenance. Public cloud providers are responsible for all maintenance and management tasks.

Disadvantages of Public Cloud

  • Security. Security and data privacy is a major concern in public cloud infrastructure. (Also read: Cloud Security 101.)
  • Control and flexibility. As providers are offering the same service to multiple clients, you always have less control of the services using the public cloud model.
  • Customization. Public cloud is a multitenant environment; so customization is very limited.
  • Customer support. Proper support and assistance is not always available.

The cloud offers a range of benefits derived from its five main characteristics; these characteristics must be present to operate as a fully-featured cloud service. You'll need to ask more questions if the CSP sales team is offering your business a cloud service and it doesn't have the following characteristics (as specified by NIST SP800-145):

  • Resource Pooling.
  • Broad Network Access.
  • Rapid Elasticity.
  • Measured Service.
  • On-Demand-Self-Service.

Make sure you are getting the true value that a cloud service can offer.

What is Private Cloud?

Private cloud—also known as "corporate" or "internal" cloud—is a cloud computing infrastructure, including hardware and software, dedicated for a single client.

Private cloud comes with the advantages of on-demand scalability, elasticity, access control, resource management and many more customization options than public cloud.

Organizations choose private cloud for multiple reasons, such as:

  • To meet regulatory guidelines.
  • To protect confidential and intellectual data.
  • To protect financial data and sensitive information.
  • To protect medical records.

Once the private cloud is built, an organization can also move to public or hybrid cloud at any point. Private cloud infrastructure costs more compared to public or hybrid models—so organizations may want to mix models to optimize affordability. (Also read: 3 Key Aspects of Effective Hybrid Cloud Management.)

Types of Private Cloud

Basic cloud infrastructure started with the simple purpose of storing data in a separate virtualized storage space and accessing it on-demand. With the progress of technology, however, the cloud environment has evolved into different forms.

The private cloud is one of the most important forms cloud infrastructure has evolved into—one that comes with improved security, flexibility and customization options. This makes it ideal for organizations looking for cloud solutions specific to their business needs.

The private cloud is also classified into two branches:

  1. Hosted private cloud.
  2. On-premise private cloud.

Let's explore each of these in more detail:

Hosted Private Cloud

Hosted private cloud infrastructure is basically a private cloud solution provided by cloud vendors in their own data centers.

Here, the cloud providers offer customized private cloud solutions specific to your business needs.

Some advantages of hosted private cloud solutions include:

  • It's easy to get additional resources to meet on-demand scalability.
  • Access to a highly skilled support team to help you with server management.
  • An efficient dashboard providing an overall understanding of cloud services.
  • Budget friendly pricing for all the managed services.
  • Easy exit from the vendor contract if not required in the future.

Disadvantages of hosted private cloud solutions include:

  • Concerns around security for your confidential data. (Also read: How Cloud Computing is Changing Cybersecurity.)
  • Limited control over cloud infrastructure.
  • Limited opportunity for customization.
  • Delays when implementing on-demand modification and/or.
  • On occasion, inefficient support teams.

On-Premise Private Cloud

On-premise private cloud is a private cloud infrastructure located on client premises.

Put differently, the physical data center is built internally at the client's location. On-premise cloud infrastructure is always more protected from external threats. However, the internal IT team must work very efficiently to manage the entire cloud setup.

Here are some advantages of on-premise private cloud solutions:

  • Complete control and management over the critical aspects like scalability, security, flexibility and configuration.
  • Ability to create the most efficient and customized cloud environment for your business.
  • Flexibility to add, remove and/or update additional hardware resources and services.
  • The option to offer instances of your data center and managed services to other businesses.
  • Facility complying with local and country-specific rules and regulations.
  • Ease of managing downtime and business continuity. (Also read: The Best Practices for Managing Cloud Applications.)

And here are some disadvantages:

  • Undertaking full responsibility for managing and maintaining your data center.
  • Expensiveness, as you have to purchase the hardware, software and other related resources.
  • Being responsible for timely updating and/or renewing the security system to keep data center safe.
  • Needing to keep proper backup data in case of hardware and/or software failure.
  • Needing to hire experts to manage your cloud platform.

Choosing the Right Cloud Model for You

Selecting the most appropriate cloud solution is a very important step for your business success. As we've discussed, there are multiple options available—from public cloud, to hybrid cloud, to hosted and on-premise private cloud. You can also incorporate any combination of these options.

As such, there are multiple parameters to consider before selecting the right cloud solution.

When to Choose Public Cloud

  • You have budget constraints. Public cloud is the least costly option and thus can be the best choice for organizations with tight budgets.
  • You have fluctuating data loads. If your organization's data load changes frequently, public infrastructure can support it efficiently.
  • You have less security concerns. Organizations without major data security issues may prefer public cloud.
  • You don't need to adhere to strict legal regultions.

When to Choose Hosted Private Cloud

  • You need something budget-friendly. Hosted private cloud is cost-effective compared to the on-premise model.
  • You need security and support. If you want the vendor to manage your private cloud, then this model is a good fit.
  • You require scalability.
  • You need failover. As this is a hosted environment, a vendor provides sufficient support for failover.

When to Choose On-Premise Private Cloud

  • You have lots of sensitive data.
  • You need customization. If you need a higher level of computing customization, on-premise private cloud can work for you.
  • Your data load doesn't fluctuate much. This model is good if you have an almost-stable data load.
  • You want absolute control. On-premise private cloud offers complete control over the infrastructure.

The Future of Cloud Computing

With the increase in cloud spending, it is evident that cloud computing will be an integral part of all business success in the future.

Let us try to identify some of the emerging trends in cloud computing:

  • Multi-cloud solutions. Also known as "hybrid" cloud solutions, multi-cloud solutions are combinations of public and private clouds. These allow organizations to leverage the benefit of low-cost public cloud and some private cloud for securing sensitive data.
  • Cloud computing and AI. Cloud plays an important role in artificial intelligence solutions: Any AI and/or machine learning application needs to process a large volume of data and cloud computing can support the processing power and bandwidth. (Also read: Machine Learning and the Cloud: A Complementary Partnership.)
  • DevSecOps. DevSecOps is a new concept where the infrastructure security is considered from the very beginning along with the development and operation.
  • Cloud and IoT. We are living in a connected world where all devices are also connected—a concept known as the "Internet of Things" (IoT). So, most of IoT solutions are cloud-enabled.
  • Serverless architecture. Serverless solutions are on the rise, as organizations do not need to invest or rent servers for their data and computation.


In the current business landscape, digital transformation is the key to success. Companies are enabling cloud transformation to scale up their business and improve efficiency. The COVID-19 pandemic has catalyzed this process—if you haven't adopted cloud infrastructure yet, you'll need to soon. If you already have, you need to ensure your infrastructure stays current to protect against evolving threats.

That means the biggest question surrounding cloud infrastructure is not whether to adopt cloud solutions, but which solution to adopt. As we've discussed, the answer to that question depends on several factors—namely the advantages and disadvantages of the solution itself and your organization's unique needs. By considering the cloud's unique strengths while evaluating its weaknesses in your unique situation, you can make the choice that's right for your organization.


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Kaushik Pal
Technology writer
Kaushik Pal
Technology writer

Kaushik is a technical architect and software consultant with over 23 years of experience in software analysis, development, architecture, design, testing and training. He has an interest in new technologies and areas of innovation. He focuses on web architecture, web technologies, Java/J2EE, open source software, WebRTC, big data and semantic technologies. He has demonstrated expertise in requirements analysis, architectural design and implementation, technical use cases and software development. His experience has covered various industries such as insurance, banking, airlines, shipping, document management and product development, etc. He has worked on a wide range of technologies ranging from large scale (IBM…