Hybrid Cloud Hosting Blog

Public vs. Private vs. Hybrid cloud - what's what?

Feb 15

Posted February 16, 2015 by  Clive Larkin

public cloud private cloud hybrid cloud

Cloud computing is an increasingly integral component of doing business, especially for those offering SaaS or selling online.

Despite this growth, the industry still hasn’t arrived a consistent set of definitions for the three main flavours of cloud computing, resulting in confusion for those migrating to the cloud for the first time.

In this post we compare and contrast the three main types of cloud solution, namely public, private and hybrid, and look at typical applications of each.

Flavours of cloud computing 

Definitions vary but, to us, the meanings of key cloud terms are as follows:

  • Cloud: A combined hardware and software platform accessed over the internet
  • Public Cloud: In a Public Cloud, virtual computing resources can be accessed by anyone (with permission) over the internet. Applications for different firms share the same resources, i.e. a multi-tenant environment where the underlying platform plays host to more than one client
  • Private Cloud: In a Private Cloud computing model, computing resources are dedicated to serving a single company. This means the hardware, software and virtual machines are all at the exclusive disposal of a single firm, i.e. a single tenant environment
  • Hybrid Cloud: A Hybrid Cloud is a combination of at least one of the above cloud computing models with any other computing model. The other model could be cloud-based, colocated or on-site and could consist of virtual or dedicated machines

Whichever cloud model is right for your business, they all confer similar benefits though to different degrees and at different cost points. Universal benefits of cloud computing include flexibility, scalability, reliability and cost reduction. So which model is best suited to your needs?

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Public Cloud

Public Cloud is the easiest model to understand and access. Public Cloud platforms are fully owned and maintained by the provider, with them creating virtual machines for your use. Utility pricing is pretty much standard and virtual machines are becoming increasingly powerful and flexible.

Strengths of Public Cloud 

Cost - Able to share their infrastructure between many clients, Public Cloud providers are able to realise economies of scale which can be passed on to you in the form of affordable, pay-as-you-go pricing.

Flexibility - Public Cloud computing offers you the greatest flexibility of all models - changing the type or number of servers you take, or migrating supplier completely, are all technically straight forward.

Elasticity – Public Cloud technology, and most SLAs, allow for a high degree of elasticity. This is great for applications with demand that is variable or has spikes – things like ticket sales or testing environments. To take advantage, your application must be cloud aware so that it can scale and utilise the additional capacity.

Uptime – Due to the high levels of resilience typically built-in to public clouds, the usually offer exceptional uptime. 

Best for

Public Cloud computing is suitable for a wide range of applications. Start-ups and established businesses alike can benefit from flexible and affordable cloud servers on which to test developments or virtualise business process software. Public Clouds may not meet industry specific data protection regulations and so may not suit businesses that are subject to these.

Private Cloud

Technically no different to the Public Cloud model at its core, Private Cloud is simply exclusively used or owned by a single organisation.

Strengths of Private Cloud

Total control - Total ownership equals total control. If created in-house, this goes without saying. If hosted with a third-party provider, anyone worth their salt will work with you to specify exactly the system you need from the ground up. This customisation could include choice of geographic locations, connectivity, bandwidth, resilience, backup options and much, much more.

Predictable performance - Through your exclusive use of a Private Cloud platform, you can have total visibility of utilisation, demand and performance. With proactive monitoring and management you can ensure your business is always running at optimum efficiency.

Best for

Private Clouds offer additional security options over Public Cloud and so can be used to run sensitive or business critical applications, or to process sensitive data such as customer payment details. They are well suited, as a result, to eCommerce and SaaS delivery amongst other things. Private Cloud will typically offer a lower total cost of ownership than Public Cloud if the compute load is consistent and not spikey. 

Hybrid Cloud

Hybrid Clouds combine computing models to leverage the strengths of each and can incorporate virtualised (Public or Private Cloud), colocated or on-site infrastructure. 

Hybrid Clouds enable firms to gain access to the benefits of cloud computing while continuing to make use of existing infrastructure. Alternatively they can be used to divide operations and data between Public and Private Clouds according to individual requirements for flexibility and security.

Best for

Hybrid Cloud systems can be configured to meet any set of individual requirements. As such there isn't any application that cannot not be catered for on a Hybrid System. Higher total costs of ownersip however, coming from the added complexity of two or more systems, mean that Hybrid Cloud is best deployed where multiple computing models are mandated or required to overcome a specific business challenge - such as reducing total costs while still utilising existing infrastructure.

Ordering off the menu

Here we’ve descried three common cloud computing models. These models form the basis for a great many of our customers' solutions. The reality is, however, that the cloud is not limited to these three models. After all, the cloud isn’t a thing – it’s a collection of technologies and techniques that can be combined to form a completely bespoke solution.

For example, it’s entirely possible for you to run several machines on a public cloud but to protect and balance them using your own dedicated firewalls and load balancers. Or you could run a private cloud, dedicated to your needs, that also backs up in real-time to a public cloud, giving you best performance during normal operation with a live back-up solution that doesn’t cost the earth. You could have public cloud machines whose data is stored on a dedicated disk pool or a private SAN. The options are limitless.

The best way to get the ideal solution for you is to think about what your application really needs and then talk to a cloud hosting provider with a track record of developing unique, fit for purpose hosting solutions for businesses like yours.


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Topics: Cloud Hosting