You want services provided dynamically according to your needs and usage-based billing? Cloud services offer these advantages. But the issue is often clouded by the sheer variety of offers. What's behind all this, and don't all variants ultimately offer ‘just’ services?
The diversity of clouds can be broken down into two categories. The first is characterized by location and answers the question of where the cloud is situated and to whom it is accessible. Here, the three traditional alternatives are the public cloud (publicly access services on a provider's system), the private cloud (closed, mostly company-own services) and the personal cloud (publicly accessible services via the Internet on distributed systems). The second category is characterized by the IT stack in which the respective cloud service is located. Here the basis is ‘Infrastructure as a Service’, where basic systems, computing power, network and storage systems are provided. Building on this is ‘Platform as a Service’ with provided run-time and/or development systems. The most well-known service option is ‘Software as a Service’. Here, a solution is quasi provided ‘per use’.
In addition, combinations of these systems and services broaden the spectrum of the cloud landscape.