Cloud computing concept.
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The stats for public clouds depict a healthy state of affairs. According to Statista, revenue in the public cloud market is projected to reach $397.9 billion in 2022, and the market’s largest segment is software as a service, which has a projected market volume of $207.2 billion this year.

With this positive information in mind and a variety of different terms in the cloud sector to consider, it’s worth understanding how the public cloud is defined, as well as its benefits, drawbacks and features.

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What are public clouds?

According to IBM, a public cloud is “a type of cloud computing in which a third-party service provider makes computing resources — which can include anything from ready-to-use software applications, to individual virtual machines, to complete enterprise-grade infrastructures and development platforms — available to users over the public Internet.”

There are three different types of public clouds:

  • 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 it is expert in and delivers the applications to clients.

Among popular public cloud service providers are AWS, IBM, Google, Microsoft, Oracle and Salesforce.

Benefits to public clouds

Frees IT staff

Third party cloud service providers manage public clouds so that IT departments don’t have to worry about managing applications infrastructure or networks at all. This allows your 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. When you engage a public cloud services provider to handle the computing for you, the cloud provider has on-staff expertise that can fill in for your own staff’s skills gaps.

Shared cost

Since a public cloud services provider supplies computing resources for many different companies, the costs of the cloud are shared. This can lower overall enterprise IT costs.

Flexible infrastructure

Public cloud infrastructures are flexible. If you need more computing power or storage, you can scale your needs upwards on the spot. Conversely, you can also downscale resources when you are through using them. In short, you pay only for what you need. Compare this with an amortized capital investment in software or hardware for your data center, where you continue to pay even when resources are dormant.

Drawbacks to public clouds

For some companies, a drawback to public clouds is that you’re sharing computing resources with others. Public cloud providers reassure their clients that client computing is kept secure and segregated, but just being in a separate computing partition and sharing resources is not secure enough for some clients.

In other situations, such as a client that must have extraordinary transaction processing speeds, the public cloud doesn’t work because it is commonly accessed over the public Internet, and data transmission rates may be too slow.

In still other cases, there is trepidation because although a public cloud services provider may have multiple data centers in different locales, providers usually unwilling to guarantee specific performance metrics for disaster recovery and failover.

Key features of public clouds

Public cloud services operate on a multi-tenant architecture. This means that the computing resources in the cloud provider’s data centers are shared between many companies, with each company operating in its own separate and secured partition.

The purpose of a public cloud is to supply all of the IT infrastructure and services that client company IT departments need to run and manage their workloads on the cloud. In most cases, each client company IT department has the choice of just how much IT management it wants to turn over to the cloud provider. A small company might want the public cloud provider to run and service all of its IT, but a large company might opt to host only some of its IT on the public cloud. Cloud services and resources are scalable and customizable for each client company.

Most public cloud providers charge on a per-use basis. Some will charge per minute or per hour of use, while others will charge per other time increments that a client company and the provider agree to. Companies that already know what they are likely to require from the cloud are in a position to enter into a multi-year fixed cost contract that is discounted because the cloud provider has the assurance that the company will be with them as a customer for a certain term of years.

On the storage side, public cloud providers often charge on a per-gigabyte basis, with some cloud providers offering a certain amount of free storage. Public cloud providers also charge additionally if a client company chooses to engage their consultants or specialists for assistance.

How to choose what’s best for you

Companies considering public cloud services should first assess their IT needs and spend.

Are they a small company that is interested in outsourcing all of their IT to the cloud, or do they want to use a public cloud only for the purpose of testing applications that they will host in-house? Are they looking for a public cloud provider with unique software and expertise in a particular area, such as sales or finance?

Needs vary from company to company, and for some companies, a public cloud service is not an option. For other companies, however, public cloud providers offer flexible IT implementation and cost options that can save them from major internal data center expenses.