Difference between public, private, and hybrid cloud

As the push to the cloud continues in verticals ranging from healthcare to content streaming, the simple question of “Public, private, or hybrid?” is one being asked with increasing frequency in IT departments around the world.

Of course, we’re talking about cloud computing.

Cloud has gained incredible traction in the last few years. Right Scale’s 2015 State of the Cloud Survey showed that more than 90% of survey respondents were on the cloud earlier this year. (The survey also found that 68% of enterprises were running less than one-fifth of their application portfolio on cloud infrastructure, showing room for growth.)

Even as more and more organisations get on board with cloud, there is significant room for growth in many organisations. The decision of whether to deploy a public, private, or hybrid cloud solution can be a difficult one for even the most experienced companies.

What is the difference between public, private and hybrid cloud? What are the benefits and disadvantages to each solution? Why might a business choose public over private cloud, or hybrid over public or private? Is there a “best” cloud solution?

Below, we’ll take a look at these questions in an attempt to help organisations that are still in the process of choosing the best solution for their business, but in a nutshell:

Public cloud is a cloud computing model in which the services and infrastructure are provided by a third-party provider and accessible to the public over the internet.
Private cloud is a cloud computing model in which the services and infrastructure are dedicated to a single organisation for their exclusive use.
Hybrid cloud is a cloud computing environment that combines both public and private cloud services, allowing organisations to leverage the benefits of both while maintaining control over their data and applications.

Public Cloud: Low Entry Cost, Speed-to-Market, Extremely Scalable

Public cloud is the most widely known solution of the three listed here.

A public cloud is managed by a single external provider like Amazon Web Services (AWS), which is used by millions of people every day. AWS gets most of the attention since they own a vast majority of the market for public clouds and have a deep set of products to choose from, but there are hundreds of other providers. The public cloud can be an inexpensive option for many businesses because resources are pooled together and users pay only for the resources they actually use.

Before the rise of cloud computing, a company in need of more storage or more computing power would need to purchase physical infrastructure (e.g. servers, cabling, power) as well as the technical support needed to back up those additional resources. Public cloud, on the other hand, is typically pay-as-you-go. In the situation described above, the company could simply purchase more storage or computing power through their cloud service provider, giving them a similar end result in a fraction of the time at a fraction of the cost.

Data in a public cloud deployment is logically separated from other users in the cloud, but still all technically housed on the same network, and in most cases the same physical hardware. This differs from an on-premise solution where data would be physically separated.

Public cloud is extremely scalable and relatively inexpensive, but is technically less secure than the private cloud or colocation because your data occupies the same space as other users. When proper precautions are taken, however, the public cloud is much more secure than many people realize.

In short, public cloud deployments are:

Inexpensive: One of the greatest benefits of a public cloud deployment is cost. Some public cloud deployments are free; most are extremely cost-effective.
Extremely scalable: Need to scale up quickly? Need to cut back for a few months while you reorganize your business? No problem.
Quick to deploy: Public cloud deployments also offer fast speed-to-market. In some cases, it’s possible to deploy within hours.
Not as secure: Because data generally shares a common physical location, it is not as secure as other deployments. Public cloud has made great strides in this area, however.
At times, not compliant: Not all public cloud providers are created equal. If your business has stringent compliance needs (e.g. HIPAA), they may be difficult or impossible to maintain in a public cloud environment.
At times, difficult to manage: Though not unique to public cloud deployments, public cloud does still need management. In fact, IDC estimates that 50% of U.S. organisations lack the headcount for effective cloud management. If your organisation isn’t structured for it, managing a public cloud deployment can be tedious and time-consuming.

With the public cloud under our belts, next, we’ll move to the private cloud.

Private Cloud: More Secure, More Control, More Expensive When Built In-House

Unlike public cloud, a private cloud is a data centr e and/or network that uses cloud computing technologies.

The obvious benefit of private cloud over a public cloud deployment is security. The business operating the private cloud has complete ownership, control, and maintenance of all the data within the private cloud environment. This is advantageous to companies that have stringent compliance requirements or other concerns about the security of their data.

Enterprises have a few options when deploying a private cloud. While some enterprises choose to purchase their own resources and manage them in their own data centre, many more companies deploy private clouds with cloud service providers. In the latter situation, the cloud service provider offers a user fully dedicated hardware, shared hardware, or some combination thereof. So-called “virtual private clouds” use shared hardware, while fully-dedicated hardware more closely mimics an enterprise purchasing and managing its own resources.

Deploying a private cloud within your own data centre means that you’ll be faced with many hardware, software, and architectural decisions, as well as challenges pertaining to resources and different skill sets. A private cloud deployment within your own data centre is an option if your organisation is willing to invest the time and resources necessary to manage it.

To summarize, private cloud deployments are:

Highly secure: Your data is housed on your hardware and controlled by your software, or is carefully managed by a cloud service provider.
Able to be tailored to specific compliance needs: Businesses that have specific compliance needs, for example HIPAA compliance, can structure and manage their private deployment such that it remains compliant.
More controllable by the user: The business operating the private cloud has more control over nearly every aspect of their deployment.
More flexible than public solutions: Businesses have many more options and thus greater flexibility in decisions on the underlying technology and services for private cloud deployments.
More expensive when built in-house: Some private clouds offered by third-party service providers can offer pricing that rivals the large public cloud prices. However, if you are building a private cloud in-house, there are more up-front costs and in most cases a higher total cost of ownership.

Which brings us to the final option: the hybrid cloud.

Hybrid Cloud: The Best of Both Clouds?

Think back to the overviews of public and private clouds above. A public cloud is scalable and quick-to-market, while a private cloud, managed internally, is more secure but less scalable.

Unsurprisingly, a hybrid cloud takes from both public and private deployments and presents a unique third deployment option which is in reality a combination of both. A hybrid cloud utilizes on-premise, colocated, and public and private cloud environments in a mix that best fits a business’ needs. It’s often viewed as the best of both clouds because it allows businesses to build a custom solution and play off of the benefits of each deployment model.

A business, for example, could keep its sensitive data on-premise or in a colocated data centre, then deploy resources on the public cloud when it needs computing power quickly. Alternatively, it could host the majority of its resources in a public cloud environment and only use colocated space in a data centre for those few things that must remain fully separated.

Hybrid cloud solutions give you the security of the private cloud when you need it, the scalability of public cloud when you need it, and the full security and control of colocation when you need it.

Don’t go building your own hybrid deployment just yet, however. Hybrid cloud requires technical expertise, a clear strategy, relevant skillsets, and ongoing investment to manage properly. A solution that mixes public cloud, private cloud, colocation, and business-run data centres is inherently complicated, and it takes a good bit of skill to be able to give a hybrid deployment the attention it deserves.

When managed properly, however, a hybrid solution can be rewarding. Hybrid cloud deployments are:

Scalable and secure: Unsurprisingly, this is the greatest benefit of a hybrid cloud deployment. A well-executed hybrid deployment gives your business the security it needs when it needs it, while at the same time remaining quickly scalable thanks to its partly public makeup. This is where the “best of both clouds” idea comes from.
Scalable: Managed properly, a hybrid cloud deployment is highly scalable. If you need more computing power now, you can invest more in the public portion of your business; the same goes for greater security and investing in private cloud.
Cost-effective: Businesses can realise cost-savings by divvying up information to the environment it’s best suited for. Data that is safe to store in a public environment stays in the public environment, more strictly-managed data can stay in the private cloud, and mission-critical applications and data can stay on-premise or in a colocated data centre.
Difficult to manage: This is the kicker. Managing a hybrid cloud strategy and deployment takes commitment and skill; it is not something to be executed without lots of thought beforehand. Companies would be well-suited to have a clear path forward before deploying a hybrid cloud solution.

Hybrid cloud must be the best of all the solutions listed here, right?

Picking a Winner: Public Cloud vs Private Cloud vs Hybrid Cloud

Many companies choose a hybrid cloud solution, due in large part to the fact that most organisations have a variety of different needs across different businesses. It’s entirely possible (and common) to have certain aspects of the business in a public cloud environment, others in a private cloud environment, and others on-premise or colocated.

Despite the increased management complexity that comes with deploying a hybrid cloud solution, hybrid solutions are becoming increasingly common these days. An important note, however, is again that what’s best for one business may not be best for another.

Ultimately, the cloud deployment that makes the most sense for an organisation will depend entirely on that organisation’s needs. For some businesses with fairly straightforward needs, a fully public cloud deployment may be just fine. For others, a fully private cloud deployment may be exactly the answer. Knowing the advantages and disadvantages of each type of cloud deployment, however, can make deploying and maintaining a full-scale solution that much easier.

In short, there’s no clear winner because each type of cloud serves a different purpose. There’s a reason all three continue to proliferate: public, private and hybrid cloud all have their own unique applications.

If, having read our overview, you’d like to learn more about the cloud solutions we offer here at Digital Realty or about which cloud model best fits your business’ needs, feel free to reach out to us via the contact page of our site, or by Facebook or Twitter. We’d love to hear from you!

Frequently asked questions

Which is an example of hybrid and private cloud?

An example of a hybrid cloud could be a company that stores sensitive customer data on a private cloud and uses a public cloud for non-sensitive operations like email and document sharing.

An example of a private cloud is a company setting up its own data centre and infrastructure to host and manage its own cloud services and resources solely for internal use.

What is hybrid cloud computing?

Hybrid cloud computing is a combination of both public and private cloud infrastructure. It allows organisations to leverage the benefits of both types of clouds, such as scalability and cost-effectiveness of public clouds, and the security and control of private clouds.

Is Azure a private cloud?

Azure is a public cloud platform offered by Microsoft. It is not a private cloud as it is owned and operated by Microsoft, which makes it publicly accessible to users.

Which cloud is better public or private?

The choice between public and private cloud depends on the specific requirements and priorities of the organisation. Public clouds generally offer more scalability, cost-effectiveness, and accessibility, while private clouds provide greater control, security, and customisation. The decision should be based on factors like data sensitivity, regulatory compliance, resource demands, and budget constraints.

Should I use private or public cloud?

The decision to use private or public cloud depends on several factors such as data sensitivity, compliance requirements, resource demands, budget, and specific business needs. Organisations should evaluate their requirements and priorities to determine which type of cloud is more suitable for their needs.

Public, Private, and Hybrid Cloud: Differences and What’s Best for Your Business?