Software as a Service (SaaS)
SaaS is a service that enables people and companies to use and pay for software on demand or for the amount of time used. This means that rather than the software being on, for example, a persons’ PC or a company’s server, they can access the application via the Internet.
Platform as a Service (PaaS)
PaaS is a development of hosting whereby companies rent servers and other components required to successfully run their websites or IT department. Once again, rather than paying ‘upfront’ for hardware, a monthly fee can be agreed upon. Furthermore, the systems can be used by other companies thereby sharing and reducing costs if necessary.
Infrastructure as a Service (IaaS)
IaaS enables companies to completely delegate or outsource the whole of their IT departments including, hardware, storage, software and internet connectivity and again pay for as the system either as a flat monthly rate or as an on demand model. So whatever is used, the company then pays for.