Public, Private and Hybrid Cloud

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In this blog post, I will document the three cloud models: public cloud, private cloud and hybrid cloud.

Kicking off the post with Public cloud which has become popular and widespread in recent years, though its been around for decades. Thanks to the advances in technology, connectivity, and demand, cloud computing is now used by millions of people and organisations around the world, for various purposes. There is no one type of cloud computing that’s right for everyone. There are several different cloud computing models, types, and services which have evolved to meet the rapidly changing technology needs of organisations including Public, Private and Hybrid Cloud.

What is Public Cloud?
In general the cloud refers to a network of servers that are connected over the Internet and provide various services and resources to users. Let me simply further, public cloud is a type of cloud computing in which a third party service provider makes computing resources available to users over the Internet. These resources can include software, platforms, or infrastructure that you can access on demand and pay only for what you use. For example, deploying virtual machines on the service providers physical hardware whilst not having to invest in your own hardware. Another example of a cloud service is Office 365 (Word, Excel, Powerpoint, Outlook etc). These services are accessed over the internet and reside on servers located in the third party service providers data centres located around the world.

There are three types of Cloud models including Public Cloud. Here they are,

Public Cloud: Public cloud is owned by a hosting provider such as Microsoft Azure, one of the largest cloud providers in the world. Microsoft Azure is a public cloud service offering resources and services to organisations and individuals around the world. Most people can get started with Microsoft Azure in a matter of minutes. A public cloud is accessed via a secure network connection, or over the internet. There are also other providers who provide cloud services such as Amazon Web Services (AWS), Google Cloud and Ali Baba Cloud.

Private Cloud: A private cloud belongs to an organisation who have built an infrastructure in their own datacentres. This is known as a private cloud and not accessible to anyone outside of the organisation. It’s accessible by the organisations employees only, therefore it’s private and not available to the public.

Hybrid Cloud: A hybrid cloud combines on-premises infrastructure, or a private cloud with a public cloud. Hybrid clouds allow data and apps to move between the two environments. Many organisations choose a hybrid cloud approach due to a number of reasons including meeting regulatory and data sovereignty requirements, taking full advantage of on-premises technology investment, addressing low latency issues or to gradually migrate to a public cloud.

So what are the benefits of the three models above. Let’s dig deeper.

Comparison of Cloud Models

Public Cloud
No capital expenditure (CapEx) is required by an organisation. Organisations don’t need to invest in expensive hardware to run their services, such as physical servers, networking equipment and datacentres, therefore, no capital expenditure (no upfront investment). In simple terms, you’re using someone else’s datacentre and hardware to run your services instead of managing and maintaining your own datacentres and hardware. The cloud provider is responsible for purchasing, maintaining and managing the physical hardware including physical servers, switches, cabling and maintenance of the datacentres. So what do organisations or individuals pay for? You pay for building/deploying resources such as virtual servers and other applications on the cloud providers hardware on a pay as you go model.

Advantages of public clouds:
Lower costs: no need to purchase hardware or software, and you pay only for the service you use.
No maintenance: your service provider is responsible for maintaining the underlying infrastructure.
Near unlimited scalability: on demand resources are available to meet your business needs.
High reliability: a vast network of servers across the world ensures against failure.
Private Cloud
With a private cloud, an organisation is responsible for purchasing hardware, such as physical servers, switches, cabling, storage, air conditioning, CCTV, backup power generators and more. The organisation is also responsible for managing and maintaining the hardware including failures with physical disks, cabling, racks, power etc. Organisations are also responsible for refreshing/recycling the hardware to ensure they’re utilising the latest technology as demands increase and hardware becomes out dated and slow. A private cloud can also be hosted by a third party service provider, but in a private cloud, the services and infrastructure are always maintained on a private network and the hardware and software are dedicated solely to your organisation.

Advantages of a private cloud:
More flexibility: your organisation can customise its cloud environment to meet specific business needs.
More control: resources are not shared with others, so higher levels of control and privacy are possible.
Hybrid CloudGives the most flexibility
As an organisation you decide where to run your resources, either in your own datacentre or in the public cloud. Because you have services running on-premises and in the public cloud, the public cloud becomes an extension of your on-premises infrastructure, known as a Hybrid cloud solution.

Advantages of the hybrid cloud:
Control: your organisation can maintain a private infrastructure for sensitive assets or workloads that require low latency.
Flexibility: you can take advantage of additional resources in the public cloud when you need them.
Cost effectiveness: with the ability to scale to the public cloud, you pay for extra computing power only when needed.
Ease: transitioning to the cloud doesn’t have to be overwhelming because you can migrate gradually, phasing in workloads over time.

What is the difference between Operational Expenditure (OpEx) and Capital Expenditure (CapEx)?
Operational Expenditure (Opex) and Capital Expenditure (Capex) are two different types of expenses that a business may incur. Opex refers to the ongoing costs that a business has to spend to run its day to day operations, such as salaries, rent, utilities, and supplies. Capex refers to the money that a business invests in fixed assets or intangible assets, such as datacentres, physical servers and other physical assets.

Now think about whether running your services on the Microsoft Azure public cloud falls under capital expenditure or operational expenditure? Operational Expenditure, right? because there is no up front cost, you deploy your services in Azure datacentres and on their hardware, therefore no upfront cost to purchase hardware or invest in physical datacentres. You pay to run your services on Azure servers and pay for what you use, therefore this ongoing cost is an operational expense to your business, not capital expenditure.

I hope this short post helps gives you a basic understanding of the difference between Public, Private and Hybrid Cloud.

If you’re interested in learning Azure, I would recommend getting started with a free Azure Fundamentals learning path available at the following link Microsoft Learn – Azure Fundamentals

As always, all feedback is welcome. Please comment below. Thank you