IAAS, PAAS, SAAS - Cloud based software
On Premises Software applications developers/companies used to buy hardware, OS, virtualization software (to run more OS on same hardware). Also they would buy storage servers and networking hardware. Then they will deploy the application managing the security, os patching, monitoring. Here they manage on premise data center. Off Premises Now part of above tasks can be availed in various off the shelf manner called iaas, paas, saas. 1. iaas will provide virtualization ready systems. Developer will need to install the guest OS, setup networking/security (network and storage is provided), install application servers middleware like tomcat and then install their application like web app. They need to take care of defining load balancing (networking hardware for Load Balancer LB will be provided). EC2 provides an IP and you can choose what OS you want. 2. paas will provide more relief where in developer will not need to worry about LB and applic...