Cloud Computing is a model which makes it possible to provide easily configurable IT means (such as networks, servers, storage, applications and services) with a minimum need of management. It enables you and us to focus on your application instead of the surrounding framework.
The fysical IT means in use are virtually shared with all applications in the same cloud and are (re-)allocated dynamically according to application usage. Since only used resources need to be payed for, the total cost of ownership (TCO) is often less high compared to when using traditional IT infrastructure. The high IT means can be allocated fast (minutes, hours) and flexibel (timeframes, capacity) and can be - if needed automatically - scaled up and scaled back down. This gives the impression of unlimited resources, which means the cloud client can use required resources at any moment.
We make a distinction between the following types of Cloud Computing:
- IaaS - Infrastructure as a Service: the server infrastructure is being provided virtually and on demand.
- PaaS - Platform as a Service: the operating system and application and/or web server are being provided as a service.
- SaaS - Software as a Service: the entire application is being provided as a service.
The Reference uses Amazon EC2 (Elastic Cloud Computing) for IaaS solutions and Microsoft Azure to develop both PaaS as SaaS solutions.