What is IAAS and how it can be used from traditional setup to the Virtual/Cloud setup ?

What is PAAS and how it can be used from development/customization of the tools ?

What is SAAS and how these can be hosted into the Virtual/Cloud setup ?

If you have a Payroll application and running regularly. And now you found Cloud infra is a sophisticated one rather using the old or outdated systems, you called a Cloud expert. And what questions you need to ask him/her ? How he should answer to provide the solutions ?

This video has the above discussions with different scenarios. Once can brush up their interview skills well on these aspects.