23 Sep Public or Private Cloud, what’s the difference?

By Anthony Carrick

The Cloud

“The Cloud” as used in technology parlance, is a concept which really means “running on someone else’s computing resources”. Cloud services are high level. They include storage, scalable virtualisation, computing resources, and communication services. Cloud services are operated by technology providers over the internet (often over a VPN for security).

Cloud computing is generally defined as scalable, elastic (resources can grow or shrink depending on usage) and generally self-serviceable.
Private Cloud and Public Cloud offer similar benefits, with the differentiator being the hosting environment and network connection. Public Cloud provides enhanced privacy and data control. In some usages, a “Private Cloud” may simply mean to host services internally, regardless of scalability.

Public Cloud

Public Cloud is available for a monthly or yearly fee. Public cloud services include:

• IaaS – Infrastructure as a Service
• PaaS – Platform as a Service
• DaaS – Database as a Service
• SaaS – Storage as a Service. (SaaS can also mean Software as a Service, a subscription based purchasing model.)

Scalability is a key benefit of Public Cloud services. Data storage capacity can be easily increased (or for block storage, you pay as you need). Extra computing instances can be activated and unused ones can be turned off. Security and reliability are two advantages to outsourcing services like DNS or authentication.

The public cloud runs on infrastructure shared between organisations to keep the cost per customer down. Of course, any one organisation’s data and resource instances are private.
“Public Cloud” is generally what the term “Cloud Computing” refers to – renting publicly available, shared computing resources rather than maintaining the physical infrastructure yourself.

Advantages of Public Cloud over Private Cloud

Infrastructure running on the public cloud can be much cheaper than on-premises (or a private cloud solution) as running costs are shared between many customers. You can also save on hosting costs by scaling down in quiet periods, and scaling up during busy periods. Such dynamic scaling is difficult to achieve with traditional approaches to hosting web content.

With no physical hardware to maintain, you save money on infrastructure and supporting overheads such as electricity and cooling. New servers are only a few clicks away. With careful selection of the cloud region, your site’s performance may be better than on your own hardware.

With large amounts of computing or data usage, public cloud solutions may provide a cost benefit in the long term.

Some Public Cloud Providers

• AWS
• Azure
• Google Cloud Platform

All of the public cloud provider’s offerings come with web-based dashboards for easy cloud service management and configuration.
CT4 partners with the major public cloud providers and can advise you on moving your infrastructure to the public cloud.

Private ‘Cloud’

The exact definition of private cloud varies depending on the context and whom you ask.

• One definition is much like the traditional public cloud service offering, but using infrastructure dedicated to each customer (still on third-party servers though).

An example of this is using AWS on a Dedicated Host. While the third party (Amazon in this case) provides and maintains the hardware, the customer has direct control over the operating systems and software installed. The entire host (physical server) is dedicated to that customer. This means the customer can use the full capabilities of the machine.

• Another usage of ‘private cloud’ is almost just a buzzword – referring to maintaining business services and functionality such as VMs, databases, and data storage on the business’ own infrastructure.
• A third, emerging use for the ‘private cloud’ concept is a hybrid approach providing scalability benefits of the public cloud, but hosted within the organisation’s datacentre.

An example of this would be utilising technologies such as Microsoft’s Azure Stack or building your own integrated compute instance and storage platform.

CT4 is currently developing a product to assist with VM setup and maintenance across multiple technology providers. See Canopy Tools’ website for more details.

Advantages of Private Cloud over Public Cloud

Definition 1: Using infrastructure and hardware owned by the third party provider but dedicated to each customer provides more control over the installed software and configuration. With full access to the hardware, the software running on the server infrastructure is unimpeded.

While more expensive than public cloud, private cloud gives the organisation more control over their data and hardware used. This means they can better comply with some data storage regulations.
Definition 2: Maintaining the organisation’s computing infrastructure in-house provides the added benefit of having complete control over the hardware used. Infrastructure maintenance costs are part of the reason why organisations are moving to cloud computing.

Definition 3: Using a hybrid approach like Azure Stack or a custom solution, may still require physical maintenance, but retains all the scalability and configuration benefits of a public cloud solution
In some cases, private cloud solutions also improve regulatory compliance with locally stored data, direct control over the hardware plus the guarantee of the single organisation using the hardware.

Some Private Cloud Providers

• AWS on a Dedicated Host
• Azure Stack
• VMware with vSphere

CT4 also partner with private cloud providers such as VMWare, Microsoft. One of our popular services is helping business to move to private cloud infrastructure.

In Conclusion

With technology accessible for both on-premises and cloud usage, we have more choices than ever before.  Private and Public cloud offer distinct and different benefits.  Thus the need to differentiate the type of “Cloud” we are talking about when discussing “Cloud” in general.

CT4 are experts in both private and public cloud solutions, partners with all the major cloud service providers. Contact CT4 today to work with your business to design a solution that fits your needs.