More and more businesses are moving away from on-premise IT solutions to cloud computing, with key benefits including increased scalability, more agile working, and even security.

But organisations considering cloud solutions are faced with a choice: to utilise a public cloud, or deploy a private cloud.

So, what’s the difference between public and private cloud computing? And which is right your business?

Public cloud

A public cloud exists off site and allows for a standardised workload for applications to be delivered over the Internet and used by many people and organisations at the same time, for example, email. The data is stored and hosted by a third party and protected by a firewall.

If you’ve ever used Google Compute Engine or Amazon Web Services, you’ve used a public cloud.

One of the main benefits of leveraging a public cloud is the ease of scalability. Public cloud resources are offered on a ‘pay-as-you-go’ basis, so an organisation can subscribe to only those services that they need, while having the option to increase (or decrease) their usage in the future.

This also means no big upfront investment. And, using a public cloud doesn’t require a business to have the same level of internal IT security skills and capabilities that would be necessary for deploying a private cloud. For these reasons, smaller businesses tend to opt for a public cloud.

Where data is stored, however, can be a concern for those considering a public cloud. Your data could be stored in a different country, and therefore governed by an entirely different set of security regulations. But, on the plus side, having no geographical restriction means all you need is a Wifi connection and a laptop to log on.

And with a vast network of servers involved in public cloud, organisations can benefit from greater reliability. If one data center was to fail, the network load would be redistributed among remaining centers, making it highly unlikely the public cloud would ever fail.

Some IT executives are still concerned about the security and reliability of a public cloud, due to historic failures like the Google lightning strike and the infamous iCloud hack. But it’s evident that, with the creation of more sophisticated systems, concerns about data storage are declining, as supported by research from RightScale’s 2017 State of the Cloud report.  

Private cloud

A private cloud offers similar benefits to a public cloud in that it provides computing as a service within a virtual environment. But, it operates through a private network that is completely controlled and used by a single organisation, either internally or hosted by a partner service provider.

A private cloud couples all the benefits of public cloud (i.e.collaboration and continuity) with greater control and security for the organisation. They can tailor it to suit their specific IT preferences and requirements. As such, it’s often the preferred cloud solution for larger organisations or those with strict information governance obligations.

With a private cloud architecture, there is also the additional benefit of flexibility in the form of cloud bursting. This is where an application can run in a private cloud until the demand for computing capacity peaks, where it can then ‘burst’ into a public cloud. This means organisations only pay for extra cloud resources when they are needed. It can be a cost-effective option for SMEs as well as larger businesses.

If purchasing and implementing the software and infrastructure yourself, initial costs are higher than they would be when moving to a public cloud. However, the long term efficiencies tend to outweigh the initial investment, especially if you contract with a third-party provider who can offer you the infrastructure and licenses as part of the arrangement.

A private cloud arguably allows for the most secure data protection. So for businesses in high security industries or that handle HIPPA (Protected Health Information) or financial data, a private cloud is certainly recommended.

However, the capacity of a private cloud can be limited by the amount of servers a company can deploy. And tighter security often means it’s more difficult to access data held in a private cloud from remote locations than it is with a public cloud implementation.


Often, an organisation experimenting with cloud solutions will take a hybrid approach, and use a configuration of both public and private clouds.

This way a company has the option to keep sensitive data in-house on a private cloud, whilst storing the rest of their systems and applications on a public cloud. An organisation may choose to trial a hybrid approach before committing to public or private cloud full time.

A hybrid cloud solution gives company’s maximum flexibility over where applications and data are hosted. However it can be costly, and use of different infrastructures requires more complex IT management.

Let’s sum up. With a public cloud an organisation leverages a third-party cloud system for storing data and applications. With a private cloud, it’s all stored on an internal cloud system controlled and maintained internally. And a hybrid cloud approach simply refers to using a mix of both public and private clouds.

Which is right for your business will depend on the size and nature of your business, as well as the goals you want to achieve - whether that’s greater security levels, ease of scalability, or freeing up internal IT resource.

The cloud FAQ for growing businesses like yours

Topics: Cloud

Chris Coupe

Written by Chris Coupe

Chris is a director at RunTech. Having spent six years in business development and management, he plays an invaluable role in seeking out new opportunities and driving the company forward.