A closer look at public cloud: Types, differences and advantages

Increased performance and security. Highly available applications, infrastructure and applications. Cost savings. Public cloud appeals to organizations eager to access a wide range of resources over the public internet.

The public cloud is a cloud computing model that enables providers to offer services to multiple organizations via the public internet. Public cloud providers make resources available through multi-tenant environments. This shared pool of virtual resources can be accessed through self-service interfaces.

These resources include everything from applications and virtual machines to development platforms and enterprise infrastructure. Modern public cloud solutions provide resources through a combination of environments.

Public cloud resources are typically available on a pay-per-usage basis. Other services may be free to access or sold on a subscription-based model. Common public cloud examples include Amazon Web Services, Gmail, Google Drive and Hotmail.

Three types of public clouds

Providers supply the IT infrastructure required to host and deploy resources in the cloud and services and tools – such as data storage, monitoring and security – that help you manage your cloud applications.

The public cloud service delivery models are:

1. Infrastructure-as-a-Service (IaaS): IaaS is the most hands-on cloud model you can select, helping you control and maintain your resources. IaaS delivers solutions like data storage, networking, servers and virtualization. You can access as much data storage or computing power as you need but must run it on your own software platform.
2. Platform-as-a-Service (PaaS): With PaaS, cloud providers deliver an entire cloud infrastructure and software platform. The data, networks, servers and infrastructure virtualization are provided through a platform comprising operating systems, runtime and middleware. This approach removes the complexity and cost of building and maintaining an on-premises IT infrastructure.
3. Software-as-a-Service (SaaS): SaaS providers deliver and maintain applications and the cloud infrastructure that supports them through web portals. SaaS is the most popular public cloud solution as it removes the hard work of managing and running applications. It also ensures you don’t have to store application data on local hard disks.

How does public cloud differ from private cloud and hybrid cloud?

The critical difference between private cloud and public cloud is that a third-party provider hosts public cloud resources. In contrast, private cloud resources are hosted internally by your organization.

A private cloud model requires you to invest in the equipment and hardware necessary to build and maintain its IT infrastructure. A common risk with this approach is that if usage decreases, you are stuck with costly resources and unused or underutilized hardware. Organizations typically use the private cloud to store highly sensitive data or meet federal and state regulations around data control.

The hybrid cloud combines the use of public cloud services and private cloud. A hybrid cloud enables you to reap the benefit of both models and choose between the two depending on your specific requirements. For example, you may store your most sensitive data in a private cloud while moving other data to the public cloud.

However, there’s a tenuous connection between public and private clouds because of their different instrumentation, orchestration and provisioning approaches. Instead of hybrid cloud, distributed cloud is the way of the future. Distributed cloud – a mix of public and private cloud usage – involves establishing strategic substations for cloud compute, storage and networking.

In “The CIO’s Guide to Distributed Cloud,” Gartner predicts, “By 2024, most cloud service platforms will provide at least some distributed cloud services that execute at the point of need.”

The major benefits of the public cloud

The most significant public cloud benefits are elasticity and scalability. This especially appeals to organizations that need to be flexible to changing workload demands. The public cloud model is also highly efficient, enabling you to pay only for the resources you use. Equally importantly, this model means you don’t pay for resources you don’t use. You also save money by not having to purchase IT infrastructure and hardware.

Other benefits of public cloud services include:

• New technology: Access new technologies and software advances as soon as they become available. Operating a private cloud could make these new services too expensive to access immediately. 
• Unlimited scalability: Expand and reduce your cloud capacity and resources to meet spikes in traffic and adapt to shifts in user demands. 
• Greater flexibility: Store and access vast volumes of data available because of the scalability of the public cloud. This is ideal for backing up applications and data to prepare for unforeseen events like emergencies and outages. 
• Higher availability and redundancy: Gain higher availability and greater redundancy based on your provider’s cloud locations. This also means end-users get faster connectivity to cloud services through your provider’s network interfaces.

Increase your chance of success with the public cloud

If you want to move workloads to the public cloud, consider working with a leader in public cloud. Unisys offers multi-cloud management, cloud observability, cloud migration and modernization, and financial analysis and optimization. For more details, learn more about Cloud Management solutions and watch a video showcasing how the cloud can unleash innovation, securely.