What is Cloud Computing Actually?

The term Cloud Computing is currently omnipresent in information technology. There are many interpretations, but no standardized or uniform definition. Cloud Computing enables the provisioning and use of IT infrastructure, platforms, and applications of all kinds as electronically available services on the web. The term Cloud is meant to indicate that the services are provided by a provider on the internet. Although there is no standardized, uniform definition of Cloud Computing, the fundamental concepts and general goals of Cloud Computing are undisputed. Cloud Computing uses virtualization and the modern web to dynamically provision resources of various kinds as electronically available services. The services should be reliably and scalably usable by multiple consumers, i.e., available both on demand and as needed. From the cloud provider’s perspective, this typically implies a multi-tenant architecture and a usage-based billing model. The concept of virtualization allows an abstract, logical view of physical resources and includes servers, data storage, networks, and software. The underlying idea is to pool physical resources together and manage them collectively. According to C. Braun, Cloud Computing is defined as follows:

By utilizing virtualized computing and storage resources and modern web technologies, Cloud Computing provides scalable, network-centric, abstracted IT infrastructures, platforms, and applications as on-demand services. Billing for these services is usage-based.

Depending on the access layer, Cloud Computing is divided into different provisioning levels.

Infrastructure as a Service (IaaS)

In the IaaS layer, users are offered an abstracted view of hardware, i.e., computers, mass storage, networks, etc. For this purpose, a user interface for managing a set of resources is provided in the Resource Set sublayer, which allows allocating parts of them for one’s own use. Typical functionalities at the user interface include creating or removing operating system images, scaling claimed capacities, or defining network topologies. The interface also provides the necessary functionalities for operational operation, such as starting and stopping operating system instances.

Platform as a Service (PaaS)

Cloud services in the PaaS layer are usually not aimed at end customers but at developers. These are development and runtime environments in which custom software can be developed or executed in a specific programming language.

Software as a Service (SaaS)

Software applications in the cloud that directly address end customers belong to the SaaS layer. On the customer side, local software installation is eliminated, as is the provision of required resources. From the perspective of the described cloud architecture, SaaS offerings can be developed and operated based on PaaS or IaaS offerings from the provider. Within SaaS offerings, a distinction can be made between application services, whose functionality is essentially based on a single simple application, and fully-fledged complex applications.

Also read our article about Cloud Computing at Blickpunkt Rosenheim