What is Public Cloud? A Comprehensive Guide

Public clouds are one of the most recognised models of cloud computing today. They’re an efficient and economical way to pool tech resources and infrastructure in a virtualised environment. Those cloud services are then offered to multiple customers by the cloud provider. Today, people and companies use public clouds for everything from online software applications, hosting, storage, and cloud-based development environments. 

Companies are spending billions on public cloud services globally, and Gartner forecasts that spending will grow over 23% this year alone to just over $332 billion. Software-as-a-Service (SaaS) is still the leader in public cloud services. However, the explosion of enterprise remote work is driving growth for Infrastructure-as-a-Service (IaaS) and Desktop-as-a-Service (DaaS) this year. 

Whether you’re already a seasoned public cloud customer or are looking to migrate to one, we’ve got you covered. We put together this comprehensive guide to public clouds that goes over what they are, their benefits, why you’d want to migrate to one, and more. 

Features of the public cloud

A public cloud is a virtualised IT model where computing resources are owned and operated by a third-party provider, delivering on-demand computing services and infrastructure to multiple organisations and users using the public Internet. For example, Microsoft Azure, Google Cloud, IBM Cloud, and Amazon Web Services (AWS.) 

(Take a look at our public cloud connectivity article that covers securing access to AWS and Azure).

Public cloud providers offer cloud-based services on an as-needed basis and typically charge a pay-per-use fee, eliminating the need for customers to host these services on their own servers or data centres. Providers use groups of virtual machines and servers at data centres to offer services to multiple customers. 

Customers can rent the use of the services on the virtual machines as a whole, or they can pay for each service individually, such as software apps, app development tools, or storage. Companies and enterprises often use public clouds for less-sensitive applications that handle unpredictable usage spikes or store infrequently accessed data. 

Contrast this with a private cloud hosted on a company’s private servers, often on-premise on their own data centre. Users must be on the corporate network or cloud to access their private cloud. 

The difference between public, private, and hybrid clouds

Before we delve deeper into the public cloud topic, we thought it wise to discuss the difference between public, private, and hybrid clouds. Public and private clouds are similar in that they offer the same types of services and capabilities (computing, storage, networking, and scalability,) but they differ in how they operate and provide those services.

Public cloud

  • Runs on multi-tenant, shared infrastructure.
  • Hardware and other IT infrastructure are owned by the provider, not the customer.
  • Accessible via the Internet.
  • Bandwidth and connectivity performance depends on the public Internet.
  • Pay-as-you-go model that offers easy scalability and flexibility.

This model is ideal for companies:

  • With predictable computing needs.
  • That may need additional resources occasionally to address spikes in demand. 
  • That use general apps and services to perform IT and business operations.

Private cloud

  • Runs on single-tenant architecture.
  • The underlying hardware and IT infrastructure can be owned by the customer or a cloud service provider for exclusive use by the customer. 
  • Only accessible by employees of that company and only on the company network. 
  • Consistent bandwidth and connectivity as there are only limited people accessing it.
  • Can be a cost-effective solution if companies use a managed private cloud hosted by a cloud service provider as the provider is responsible for investing in infrastructure and maintenance. 
  • Depending on the private cloud topography, it can be difficult to scale up or down as the flexibility relies on the infrastructure at hand. 

This model is ideal for companies:

  • In highly regulated industries.
  • That deal with sensitive data and information.
  • That require robust control and security over their IT infrastructure.
  • That can afford to invest in high performance and highly-available technologies. 

Hybrid cloud

  • Combination of private and public clouds.
  • Companies can decide which model to use for their specific needs. E.g., Store sensitive data on a private cloud and use a public one for non-sensitive business services. 
  • Highly flexible as companies can move workloads between the two cloud types as needed for optimal performance and cost-effectiveness. 
  • Offers the right blend of security and compliance for companies working within industry- or country- specific guidelines.
  • Apps and data workloads can share resources between the public and private cloud based on organisational business and technical policies around security, performance,  scalability, and cost-efficiency.

This model is ideal for companies:

  • Facing different IT security, regulatory, and performance requirements.
  • Wanting to increase their security posture on existing cloud solutions.
  • Looking to optimise their cloud investments without compromising on the value that public and private clouds deliver.
  • Seeking to strategically approach their cloud investments to ensure they’re always using the best cloud service model available in the market.

How public clouds work

Looking deeper into the technical details, providers supply the infrastructure needed to host, deploy, and use apps and services in the cloud, so customers don’t have to. Public clouds generally encompass many different technologies, features, capabilities, hardware, and software. Generally speaking, they consist of:

  • On-demand computing;
  • Self-service provisioning;
  • Resource pooling;
  • High scalability;
  • Pay-per-use pricing (usually by service or number of users;)
  • High availability and resiliency;
  • The latest in security; and
  • Broad network access, usually via the Internet.

Public cloud providers typically also offer tools and services to help customers manage their cloud applications, such as data storage, security, and monitoring. Customers can usually check in on the health of their public cloud services through a provider portal to see stats on performance, usage, and more.

Users who connect to a public cloud typically don’t notice anything different from their usual computing experience. The apps or services they use every day, such as a file-sharing app, CRM, or video conferencing tool, are connected to the cloud on the backend. To them, the apps or services just “work.” 

Security in the public cloud

Previous public cloud versions were a bit of the wild west, and security breaches were common. That made every IT leader hesitate to move sensitive data or applications to the cloud. Today, however, the public cloud security is the highest it’s ever been and often outstrips on-premise security solutions. 

McAfee found that 52% of companies today experience better security in the cloud than in on-premise environments. And Gartner found that cloud IaaS workloads experienced 60% fewer security incidents last year than those in traditional data centres. 

Cloud security is at such a high level partly because large players like Google, Amazon, and Microsoft Azure have had to become experts if they wanted to stay in business. Hackers worldwide have been attacking them for years, so they had to invest heavily in security.

While public cloud providers do their expert best to keep the cloud safe, the weakest part of the security net is user access. According to SailPoint, 97% of cloud IaaS customers reported user access problems (that could be anything from defining incorrect user access profiles to omitting to develop a user removal process for employees.) 

Regardless, public clouds are very safe today as providers have robust security protocols and processes created, maintained, and enforced by experts in cybersecurity. Companies can rest assured that their data is safe both in the cloud and as it moves to and from it. 

Why use public clouds?

Many companies look to public clouds as a way of scaling their existing IT resources. They can do it on-demand without committing to an expensive investment in new physical IT infrastructure. For example, it’s easier to buy more cloud storage space if you need it today without having to buy more servers and deploy them into your network. 

Many companies are moving portions of their infrastructure to the public cloud because:

  1. They’re flexible and scalable, adjusting as needed to their variable workload demands through logically separated cloud locations. 
  2. They offer greater efficiency, and fewer wasted IT resources since they pay only for what they use. 
  3. They reduce spending on hardware and on-premises infrastructures by passing the cost of purchasing and maintaining IT equipment to the cloud service provider.
  4. They free in-house IT staff from overhead maintenance tasks and leave them available to work on higher-value tasks such as developing new products or refining business processes.  
  5. They give early and instant access to new technologies, such as machine learning and AI, which many customers can’t afford on their own.
  6. They let companies try out a service before committing to a fully paid contract or licence agreement. 
  7. They’re highly reliable and resilient because of the geographically dispersed data centres with redundant configurations and features. 
  8. They give companies more visibility into the data they store and the resources they use through built-in data analytics. Most companies don’t know what they have and how they use it, and public cloud services can perform analytics on high volumes and different data types to generate business insights. 

While these are great benefits to using the public cloud, some drawbacks may still give IT managers pause. For example:

  • Exponentially increasing costs: Companies today use an average of 805 distinct cloud apps per month in a combination of free, freemium, and paid services. Cloud apps are typically cheaper than on-premise, but complex cloud costs and pricing models could make it difficult to track spending.
  • Control challenges within the tech stack: Each cloud provider has different configuration options and control features, making it challenging for IT staff to integrate them all into the tech stack. Add in the data separation issues for remote users, and adherence to industry- and country- specific guidelines and overall control becomes a nightmare. 
  • Vendor lock-in: Many companies are restricted to apps and services from vendors they already have a relationship with. You may be forced to purchase inferior services that don’t quite meet your requirements or, on the other hand, use one that is overkill for your needs. And all because of a prior relationship or licensing agreement. 
  • Security challenges: Public clouds are generally more secure today, but trying to deploy the same security policies used on your internal resources to a public cloud service may be very difficult. You may be constrained to use the cloud’s security options, which may not meet your company’s or industry’s standards. 

Your public cloud options

Today’s public cloud market (including IaaS, PaaS, and SaaS services)  is dominated by five companies holding nearly 40% of the market: Amazon Web Services (AWS,) Microsoft, Salesforce.com, Google, and Oracle. That leaves more than 60% of the market to others to deliver targeted IaaS, PaaS, SaaS, and Desktop-as-a-Service (DaaS) apps and services. For example, ServiceNow, Workday, MuleSoft, Cloudways, and DigitalOcean. Spending on public cloud services is forecast to grow to over $332 billion in 2021, with IaaS and DaaS experiencing the highest growth, according to Gartner.

Here’s a quick list of the categories of public cloud services. 

Software-as-a-Service (SaaS): The category most people are familiar with, SaaS delivers cloud-hosted software apps to users. Instead of installing them on a local computer or device, these apps reside in the cloud and are accessed through a web browser or an API.

Infrastructure-as-a-Service (IaaS): This category offers on-demand computing, networking, and storage resources over the Internet or through dedicated API connections. Access can be done directly to the underlying hardware, also known as bare metal, or, more commonly, through virtualised services. 

Platform-as-a-Service (PaaS): PaaS offers application developers a complete platform to build, run, and manage applications. It includes all the necessary hardware, software, and infrastructure and the entire platform is managed by the cloud provider. 

Desktop-as-a-Service (DaaS): This category securely delivers virtual apps and desktops from the cloud to any device through a web browser or secure app downloaded to the device. It’s typically used to provision secure SaaS and legacy apps for employees.

Disaster recovery-as-a-Service (DRaaS): This category reliably and cost effectively replicates your critical systems for disaster recovery purposes. It supports your continuity plans to mitigate risk while maintaining up time for your company if disaster strikes. 

There are different types of public cloud services within each category, such as computing, storage, serverless products, containers, and more. Each one offers features and benefits that make them a good choice for your company. 

Migrating to a public cloud

Companies have various reasons for migrating to a public cloud. Security and data protection is the top reason, according to one survey. 

Top drivers for cloud migration insights chart

Source: Deloitte

Data modernisation and cost and performance improvements of the IT organisation round out the top three, but there are many other reasons to migrate to the cloud

1. Upcoming IT contract renewals

Many companies have contracts with data centres, software companies, and other providers that must be periodically renewed. You look at the performance, usage, and cost as you decide whether to renew or move to a new service, like a cloud solution. Public cloud agreements are less restrictive as they’re usually just a pay-as-you-go model, making it more cost-effective. 

2. Increased capacity or needs

It can be challenging to scale up tech, no matter if it’s because your business is growing or you have seasonal needs. Being able to rapidly and efficiently scale up or down is a huge benefit to moving to the public cloud. You skip the overage penalty costs and simply move up or down to a new subscription model as you need. 

3. Product development benefits

Companies who use public clouds often save time and money when developing new products because of the dynamic provisioning and pay-as-you-go cost model. They can quickly prototype new ideas, release finalised products to market faster, and realise the new revenues in shorter timelines. 

4. Acquisitions

Merging companies is challenging because of the different tech landscapes and data involved. Doing this across multiple private clouds or data centres while juggling all the different service contracts and licences can be confusing. Not to mention, it can lead to unintentional cost overruns and duplication of services. Moving data and apps into the cloud after an acquisition can be much easier with a public cloud. You can accommodate new locations, applications, and employees more efficiently, resulting in a smoother transition for all involved.

5. New or existing data compliance needs

Various industries like finance and healthcare have strict data regulations that must be followed. And if you’re a global company, you can add in additional local laws like GDPR too. All of which makes it challenging for IT teams to manage on their own. Most public cloud providers are already compliant with these regulations, removing some of the compliance burden from your company’s IT team. 

6. End-of-life or sunsetting processes

IT teams are always looking for the right time to replace old software or hardware with the latest version. Increasingly, companies are looking at ways to replicate or replace those services in a public cloud instead of replacing them with a newer model. Migrating to the cloud means companies can decommission old hardware and let licences lapse while getting all the benefits of the cloud. 

Final thoughts

Today, many companies are using public cloud services, from the front- to back- end of their business. They deliver both the operational and business-critical apps and services today’s companies need. Public clouds provide infrastructure and services to companies in an efficient, cost-effective, and secure way, even better than private clouds. And without the added time, effort, and cost of other solutions.

Redcentric has the experience, skills, and technology to deliver the right public cloud solution to our customers. We’ll help you migrate to a public cloud and set you up with the right mix of IaaS, storage, PaaS, and backup systems that’ll transform the way your company works. Contact us today to discover your unique cloud roadmap. We’re here to help.

Related Posts

What is a cloud consultant

What is a cloud consultant?

A cloud consultant is an IT professional who specialises in cloud technology and solutions, including having an in-depth understanding of leading cloud providers, such as AWS and Microsoft Azure....


What is Microsoft Azure?

Explore all there is to know about Microsoft Azure, including how it works, Azure’s services and features, and the benefits of this global cloud platform.

Why Redcentric IaaS

What is cloud native computing?

Cloud native refers to software-first computing, with infrastructure that’s specifically designed around the cloud environment – rather than as an added feature to existing hardware or physical...



0800 983 2522 sayhello@redcentricplc.com