Cloud computing can be the ability to use applications on the Internet that store and protect data while Providing a service anything including email, sales force automation and tax preparation.
It can be using a storage cloud to hold application, business, and personal data.In a cloudcomputing environment, the entire data resides over a set ofnetworked resources, enabling the data to be accessed throughvirtual machines.It aims to construct a perfectsystem with powerful computing capability through a large number of relatively low-cost computing entity, and usingthe advanced business models like SaaS (Software as a Service), PaaS (Platform as a Service), IaaS (Infrastructure asa Service).During this paper, we described Cloud Computing,service model, deployement model and architecture.Service Models of Cloud ComputingCloud Computing has various different service models such as Infrastructure as a Service (IAAS), Platform as aService (PAAS), and Software as a Service (SAAS).i.
Infrastructure as a Service (IAAS)Cloud consumers can directly use IT infrastructures (processing, storage, networks, and other fundamentalcomputing resources) provided in the IaaS cloud. Iaas cloud provides “Virtualization” in order tointegrate/decompose physical resources in an ad-hoc manner to meet growing or shrinking resource demand fromcloud consumers. An example of IaaS is Amazon’s EC2.ii.
Platform as a Service (PAAS)PaaS provides a development platform that supports the full “Software Lifecycle” which allows cloud consumers todevelop their cloud services and applications (e.g. SaaS) directly on the PaaS cloud. The main difference betweenSaaS and PaaS is that SaaS only hosts completed cloud applications whereas PaaS offers a development platformthat hosts both completed and in-progress cloud applications. Example of PaaS is Google AppEngine.iii.
Software as a Service (SAAS)Cloud consumers can release their applications on a hosting environment, which can be accessed through internetfrom various clients (e.g. web browser, PDA, etc.) by application clients. Examples of SaaS are SalesForce.com,Google Docs, and Google Mail.