A cloud service describes the provision of IT resources such as computing power, storage, networks, platforms, or applications via the internet. An external provider operates the required infrastructure, while users utilize these resources flexibly and as needed. This eliminates the need for in-house investments in hardware, while services can be scaled quickly. Providers typically bill usage according to the pay-per-use principle, so costs are incurred only for resources actually used. In addition, users access the services directly via standardized interfaces such as web browsers or APIs.
To clearly structure the different service scopes, cloud services are divided into three successive layers. These layers differ primarily in the extent to which the provider or the user is responsible for operation, maintenance, and administration.
At the infrastructure layer, the cloud provider delivers basic IT resources such as servers, storage, and networks in virtualized form. While the provider operates and maintains the physical hardware, the user independently installs and manages operating systems, runtime environments, and applications. This gives companies a high level of control over their systems while still benefiting from the flexibility of the cloud.
Goal: High adaptability while outsourcing hardware management.
Building on this, the platform layer provides complete development and runtime environments. In addition to operating systems, users gain access to databases, middleware, and development tools. This allows developers to focus more on writing, testing, and deploying applications, as the provider takes care of the underlying technical foundation.
Goal: Faster, more efficient software development with reduced administrative effort.
At the application layer, the provider delivers fully finished applications that users can use directly via the internet. Because the provider handles operations as well as maintenance, updates, and security, users do not need to deal with technical details. Instead, they use the software immediately, from any location.
Goal: Simple, immediate use of software without installation and maintenance effort.
Overall, cloud services enable flexible, scalable, and cost-efficient use of IT resources. While users still handle many administrative tasks themselves at the infrastructure layer, this effort decreases with each higher layer. At the same time, convenience, automation, and user-friendliness increase, enabling companies to tailor their IT precisely to their requirements.
