The four common Cloud Deployment models are –
Public Cloud
Private Cloud
Hybrid Cloud
Community Cloud
Cloud computing is offered through three different service models. Each model is dedicated to satisfying different business requirements. The three main cloud computing models are Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS).
Software as a Servie (SaaS): When cloud users are not able to buy software's they can rent it from cloud service ..The single virtual software application is serviced to multiple users.. Examples: Google doc, Microsoft share Point..
Platform as a Service (Paas): When the cloud users need to develop their application and run it on a third party cloud service provider platform they can go for PaaS.. The cloud customers will develop their applications on virtualized cloud platforms and execute them.. Examples:Sales force engine,Google app engine for python..
Infrastructure as a service ( IaaS): It delivers infrastructure centric resources like storage,servers,network and desktop to be assessed by cloud customers through service based interface with internet for measures cost for the utilized resources.. Examples: Amazon EC2 for compute,Flexi Scale, Rackspace..