Cloud computing has drastically changed the way conventional IT teams work and the way they utilize computational resources. With its pay-as-you-go model, clients can access unlimited computing resources just by signing up for the service. Platform-As-A-Service and Infrastructure-As-A-Service are two popular variants through which IT users bank upon the coast effective computing offerings provided by cloud providers.

Infrastructure-As-A-Service: IaaS service providers let you access virtual machines on demand based on your requirements. The virtual machine could be a bare bones computing system or one which comes loaded with a set of software. The memory requirements and CPU usage has to be managed by the user. Excellent examples for IaaS include Amazon EC2, Google Compute Engine and Azure.

Platform-As-A-Service: PaaS services include provisioning of an application on a platform for the client to use without bothering about the memory or CPU requirements. PaaS users are only concerned about the platform and the application they are working on. This is useful for clients who are interested in building a solution or need to work on an application for a specific need. The best examples for PaaS service providers include Google App Engine and EngineYard.

For businesses who want to run similar services or applications (IaaS or PaaS) hosted on their own resources instead of a public provider platform, may move on to open source frameworks like AppScale which can be run both on public or private clouds.