What is the Public Cloud?

The Public Cloud is an IT service where busi­ness­es or in­di­vid­u­als access resources such as computing power, storage, or ap­pli­ca­tions over the public internet from an external provider. These resources are delivered on demand and operated on a scalable in­fra­struc­ture shared with other users.

What is the Public Cloud? The de­f­i­n­i­tion

The Public Cloud is a de­ploy­ment model of cloud computing. It offers on-demand access to a connected pool of computing resources that are flexibly scalable and available to a wide range of users over the public internet. Public cloud services provide software, in­fra­struc­ture, and platforms on a pay-as-you-go basis. Public Clouds are scalable and typically operate on a self-service model—if you need more features or computing power, you simply scale up on your own.

How does a Public Cloud work?

The Public Cloud is based on the principle of providing IT resources—such as computing power, storage, networks, or software—over the public internet. These resources come from large data centers operated by spe­cial­ized providers. Users access these services through a web-based interface or ap­pli­ca­tion pro­gram­ming in­ter­faces (APIs), requiring only an internet-enabled device. Powerful local hardware is not necessary, since the actual pro­cess­ing takes place in the cloud. This type of resource-efficient hardware is known as a “lean client” or “thin client”.

In the back­ground, the in­fra­struc­ture relies on vir­tu­al­iza­tion. This means that multiple customers use virtual machines on the same physical hardware, while remaining strictly isolated from one another. This approach allows for flexible and efficient use of resources, which can be scaled up or down as needed. Resource al­lo­ca­tion is handled au­to­mat­i­cal­ly by a system called mid­dle­ware, which acts as a bridge between hardware and ap­pli­ca­tions. It ensures that tasks are in­tel­li­gent­ly dis­trib­uted across multiple servers.

To ensure high avail­abil­i­ty, providers rely on re­dun­dan­cy: data and services are stored multiple times across different servers. If one instance fails, a backup au­to­mat­i­cal­ly takes over. An even higher level of security is achieved through geo-re­dun­dan­cy, where the same data is stored in data centers located in different ge­o­graph­ic regions.

Ad­van­tages and dis­ad­van­tages of the Public Cloud

The Public Cloud offers many benefits for busi­ness­es, es­pe­cial­ly when it comes to ef­fi­cien­cy and scal­a­bil­i­ty. Signing up and getting started is straight­for­ward, and billing is based either on actual usage or on a sub­scrip­tion model. This largely elim­i­nates the need to invest in dedicated hardware, helping companies save costs. There’s also no need to purchase expensive software licenses for every employee, as many ap­pli­ca­tions are provided on demand. Cloud providers also offer high avail­abil­i­ty and strong security: their server farms are monitored and main­tained by experts around the clock. Geo-redundant systems ensure re­li­a­bil­i­ty across multiple locations. By sharing hardware and using it more ef­fi­cient­ly, the Public Cloud is also con­sid­ered more en­vi­ron­men­tal­ly friendly than private server in­fra­struc­tures.

However, there are also some lim­i­ta­tions. For example, the GDPR requires that certain types of personal data must not leave the company or the European Union. This means not all cloud providers are suitable for every use case. Since access takes place over the public internet, the Public Cloud is generally con­sid­ered more vul­ner­a­ble to security risks. In addition, customers share the same physical in­fra­struc­ture, which can sometimes affect per­for­mance or avail­abil­i­ty. Some providers also reserve the right to restrict certain features or con­fig­u­ra­tions, which can limit the flex­i­bil­i­ty customers have in using the cloud.

The dif­fer­ence compared to the private cloud

The fun­da­men­tal dif­fer­ence between the Public and Private Cloud lies in the dis­tinc­tion between public and private access. In the world of cloud computing, there are three main types of access models. On one side is the Public Cloud, which is available to anyone with an internet con­nec­tion and the necessary budget. On the other side is the Private Cloud, which is isolated from public access. Each model has its own ad­van­tages and dis­ad­van­tages. For this reason, some companies opt for a Hybrid Cloud, which aims to combine the best of both worlds.

What all three models have in common is their stream­lin­ing effect on hardware and software resource con­sump­tion within a company. When the IT en­vi­ron­ment is cen­tral­ized in the cloud, potential per­for­mance peaks are dis­trib­uted across the virtual servers in use.

Use cases for the Public Cloud

The Public Cloud offers a wide range of use cases for busi­ness­es of all sizes and in­dus­tries. A key area of ap­pli­ca­tion is In­fra­struc­ture as a Service (IaaS), where companies can flexibly obtain essential IT resources such as virtual servers, storage, or net­work­ing through the cloud. This is es­pe­cial­ly well-suited for de­vel­op­ment en­vi­ron­ments, test systems, or running scalable web ap­pli­ca­tions.

In the area of Platform as a Service (PaaS), providers deliver complete de­vel­op­ment and runtime en­vi­ron­ments. These are ideal for de­vel­op­ers who want to focus on coding without having to manage the un­der­ly­ing in­fra­struc­ture.

Another common use case is Software as a Service (SaaS) models. These have become standard in the daily op­er­a­tions of many busi­ness­es: ap­pli­ca­tions like Microsoft 365, Google Workspace, or cloud-based CRM systems are accessed directly through a browser—without the need for local in­stal­la­tion or main­te­nance. The cloud is now also a key tech­nol­o­gy for backup and archiving solutions, data analytics, ar­ti­fi­cial in­tel­li­gence, video streaming, e-commerce, and remote work.

What to consider when choosing a Public Cloud provider

Whether IaaS, SaaS, or PaaS, there is a wide range of Public Cloud services on offer. Quality standards vary, however, and providers work dif­fer­ent­ly. You will be able to find a service that meets your needs and fits your business.

Value for money

For budget planning, it’s essential to factor in recurring expenses such as Private Cloud sub­scrip­tions. Whether a higher price is worth it depends on the features offered—and whether you actually use all of them. A large in­fra­struc­ture with a fully func­tion­al de­vel­op­ment en­vi­ron­ment is only necessary if you plan to build and run your own ap­pli­ca­tions. However, cutting back on es­sen­tials will likely have a negative impact on your workflow.

Typically, you build your service package yourself through your user account. However, some providers may not offer all the features you need. Most providers enforce what’s known as vendor lock-in—a de­pen­den­cy on the provider—which makes it harder for customers to switch services. In some cases, they use pro­pri­etary formats that are not com­pat­i­ble with other ap­pli­ca­tions, or only with sig­nif­i­cant effort.

Will­ing­ness to innovate

Are you con­stant­ly evolving and testing your own skills? Anyone who develops creative ideas in the cloud must be able to rely on their service provider. Data security should not be a problem due to re­dun­dan­cy. However, in order for you to be able to continue to make progress, your service provider must also remain in­no­v­a­tive and offer you new op­por­tu­ni­ties. In­di­ca­tions of an in­no­v­a­tive company are regular updates and an action plan that has been demon­stra­bly adhered to. Sus­tain­able growth is a sign of re­li­a­bil­i­ty, while too rapid growth quickly bursts the bubble of success.

User-friend­li­ness and func­tion­al­i­ty

A service provider who does not con­stant­ly reinvent them­selves is something you can live with. However, a service provider who does not offer the basic functions you need for your website is useless. They should include tools and services that make your work easier. User-friendly public cloud providers fa­cil­i­tate com­mu­ni­ca­tion between people and between ap­pli­ca­tions. This also applies to com­mu­ni­ca­tion between the experts from the cloud provider team and your own IT team. Without trans­par­ent com­mu­ni­ca­tion, processes slow down and employees may lose mo­ti­va­tion. Ad­just­ments should be as simple as possible and im­ple­ment­ed smoothly.

Security

If you operate software or even entire de­vel­op­ment en­vi­ron­ments, including a com­mu­ni­ca­tion platform through a public cloud, you in­evitably put your personal data on the internet. You have sole access to your data through an interface assigned to your company. You may, however, share the server on which this data is stored with other users. In principle, your company is liable if data pro­tec­tion vi­o­la­tions occur.

If your company is based in the United States, you must ensure com­pli­ance with data pro­tec­tion reg­u­la­tions such as the Cal­i­for­nia Consumer Privacy Act (CCPA) and industry-specific standards like HIPAA or GLBA, depending on your sector. When storing personal or sensitive data in the cloud, it’s important to choose a provider that operates under U.S. law, offers trans­par­ent and compliant data handling agree­ments, and—ideally—can guarantee that your data is stored on servers located within the United States.

Mobility

With cloud computing, companies rely on a lean client. This “slim” client is your device or a program that cannot function without support from a server. The purpose of light­weight hardware is twofold: lower ac­qui­si­tion and main­te­nance costs, and the ability to freely scale its ca­pa­bil­i­ties—thanks to vir­tu­al­iza­tion on the cloud server.

So far, so good—but what about mobile devices? Make sure your cloud provider supports com­pat­i­ble platforms that enable mobile SaaS for your business. The same applies to ap­pli­ca­tions your customers access on their mobile devices.