"Cloud Computing" defines how the application should be installed

 

1 : On premises the Appilcation is installed and runs on computers on the premises (in the building) the compagny

 

2 : Infrastructure as a Service (IAAS): Application is installed and runs on an external provider infrastructure (physical or virtual machines and other additional resources such as images in a virtual-machine image-library, raw (block) and file-based storage, firewalls, load balancers, IP addresses, virtual local area networks (VLANs), and software bundles)

 

3 : Platform as a Service (PAAS): Application is installed and runs on an external provider computing platform including operating system, programming language execution environment, database, and web server. Internal/external developers can develop and run their software solutions on a cloud platform

 

4 : Software as a Service (SAAS): Application is designed, installed and runs by an external delivery partner. Some customization can be implemented during the design phase