The stats for the public cloud depict a healthy state of affairs. According to Statista, revenue in the market is projected to reach $934.28 billion in 2025. Furthermore, the market’s largest segment is Software as a Service, which has a projected market volume of $390.46 billion this year.
With this in mind, it’s worth understanding what the public cloud is, how it works, its key benefits, drawbacks, and features.
SEE: What Is Private Cloud? (TechRepublic)
What is the public cloud?
The public cloud is a type of cloud computing where a third-party service provider offers computing resources, including software applications, virtual machines, and complete infrastructures, over the public internet. These resources are shared among multiple users but are kept secure and segregated to ensure privacy and security.
There are three types:
- Infrastructure as a Service: Where the cloud provider furnishes all computing infrastructure components such as servers, storage, and virtualized systems.
- Platform as a Service: Where the cloud provider furnishes hardware and software tools that clients use to develop their own applications.
- Software as a Service: Where the cloud provider hosts applications.
Key features of the public cloud
- Multitenancy: Operates on a multitenant architecture, meaning computing resources are shared among multiple users, who operate in separate and secure partitions within the cloud.
- Resource pooling: The architecture is designed to pool resources such as processing power, network bandwidth, and storage. This pooled model increases efficiency and allows for dynamic distribution of resources as per user demand.
- Broad network access: Typically accessible over the internet, allowing users to access services and manage resources from anywhere using a variety of devices like laptops, smartphones, and tablets.
- On-demand self-service: Users can provision computing resources as needed, excluding human involvement with the service provider. This on-demand model provides flexibility and speed in deploying applications.
- Elasticity and scalability: Designed to be highly elastic and scalable. Users can quickly scale up resources to handle peak loads and scale down when demand decreases, often automatically.
- Metered billing: Users are billed based on their usage of resources. This pay-as-you-go model eliminates the need for significant upfront capital expenditure on IT infrastructure.
SEE: What Is Hybrid Cloud? (TechRepublic)
How does the public cloud work?
Public cloud operates on a shared infrastructure model, where multiple users access the same physical resources such as servers, storage, and network devices. These resources are owned and managed by a third-party cloud service provider and are divided into multiple virtual instances through virtualization. Each user accesses their own virtual environment, which appears as a separate, private network, despite the shared underlying hardware.
The allocation of resources is managed by the cloud service provider’s management software, often referred to as the cloud orchestration platform. This platform enables the automatic allocation of virtual resources based on user requests, ranging from a single virtual machine to a complex multi-tier application environment. The public cloud also employs automation for resource provisioning, scaling, and management, allowing users to quickly adjust resources based on their needs.
It uses distributed storage systems for data management, spreading data across multiple physical disks in different locations for high availability, redundancy, and fast data access. Security measures, including encryption, identity and access management, and physical security controls, are implemented to protect the shared infrastructure and users’ data.
SEE: Cloud Storage Management Checklist (TechRepublic Premium)
Benefits of the public cloud
Frees IT staff
Because it is managed by third-party service providers, IT departments don’t have to worry about managing applications infrastructure or networks at all. This allows IT staff to focus on other work.
Dedicated experts
In some cases, especially for smaller companies, on-staff expertise may be lacking for IT platforms and services. Public cloud services providers typically have on-staff expertise that can handle computing tasks and fill in any IT skills gaps.
Shared cost
Since a provider supplies computing resources for many companies, the costs of the cloud are shared. This can lower overall enterprise IT costs, especially for businesses with fluctuating needs.
Flexible infrastructure
If more computing power or storage is required, businesses can scale their needs upwards on the spot. Conversely, businesses can also downscale resources when they’re no longer required.
Compared to an amortized capital investment in software or hardware for data centers, where businesses continue to pay even when resources are dormant, the public cloud tends to be more flexible and affordable.
SEE: IT Leader’s Guide to Software as a Service (TechRepublic Premium)
Drawbacks of the public cloud
Shared resources
Even though providers ensure client computing is kept secure and segregated, being in a shared environment may not be secure enough for some clients, especially those dealing with sensitive data.
Potential for slower data transmission
For clients that require exceptional transaction processing speeds, they may not be the best choice. Since the public cloud is commonly accessed over the public internet, data transmission rates may be slower compared to private networks. This could impact real-time or latency-sensitive applications.
Limited control and customization
The provider controls and manages the underlying infrastructure. As a result, customers have limited control over the hardware and software and may not be able to customize the environment to the same extent as they could with a private cloud or on-premises infrastructure.
Compliance and regulatory concerns
For organizations operating in heavily regulated industries such as healthcare or finance, compliance can be a challenge. Data residency and privacy laws may restrict where data can be stored and processed, which can be difficult to manage in a public cloud environment.
SEE: Hiring Kit: Cloud Engineer (TechRepublic Premium)
Public cloud pricing
The cost of services can vary widely depending on the specific services used, the amount of resources consumed, and the pricing model of the cloud provider. It’s challenging to provide an average cost due to these variables, so pay-as-you-go models are more common.
These models ensure businesses only pay for the resources they use, so the public cloud can be more cost-effective. However, costs can quickly add up with heavy usage.
SEE: Quick Glossary: Cloud Platform Services (TechRepublic Premium)
Public cloud security
The cloud provider and the customer share responsibility for security. The provider secures the underlying infrastructure, including the physical data centers, servers, and networking hardware. They typically offer a range of security features, including encryption, firewalls, and access controls.
However, customers are responsible for securing their data and applications within the cloud, including managing user access, protecting data privacy, and complying with relevant regulations.
SEE: 10 Must-Read Books on Cloud Computing (TechRepublic Premium)
Public cloud providers
Some top public cloud providers include Amazon Web Services, Microsoft Azure, and Google Cloud.
Amazon Web Services
AWS offers an array of services spanning compute, analytics, networking, management tools, IoT, mobile, storage, databases, developer tools, security, and enterprise applications. AWS is known for its scalability, security, and extensive suite of cloud services.
Microsoft Azure
Microsoft Azure provides a huge variety of cloud services covering computing, storage, networking, and analytics. Azure is well-integrated with other Microsoft products, making it a popular choice for organizations that use a lot of Microsoft software.
Google Cloud Platform
GCP offers services that run on the same infrastructure that Google uses internally for its consumer-facing products such as YouTube and Google Search. GCP provides services such as computing, data storage, data analytics, and machine learning. It’s popular for its strong capabilities in data analytics, AI, ML, and its competitive pricing.
SEE: How to Manage Your Organization’s Cloud Security Posture (TechRepublic Premium)
Should your organization use the public cloud?
Organizations considering public cloud services should initiate their decision-making process by evaluating their specific IT requirements and budget. They should think about factors such as the size of the organization and the intended use of the cloud. For instance, a smaller company might be interested in completely transferring its IT operations to the cloud, while another might only want to use the public cloud for application testing before hosting them in-house.
Certain organizations might be seeking a provider that offers specialized software and expertise in a specific domain, such as sales or finance. The needs are diverse and vary from one organization to another and for some, public cloud services might not be a suitable option. However, for many others, public cloud providers present flexible IT deployment and cost alternatives that can prevent significant internal data center expenditures.
For a more detailed look at this subject, check out the IT Leader’s Guide to the Public Cloud at TechRepublic Premium.
This article was originally published in October 2022. An update was made by the current author in July 2023. The latest update was by Antony Peyton in June 2025.
