Are cloud applications the same thing as Saas? Or is there some important difference?

The simple way to distinguish between SaaS (software as a service) and Cloud Applications is to think of SaaS as a business model and Cloud Applications as a technical solution.

SaaS refers to paying for software on a subscription model. Usually one fee covers a number of things you would purchase separately in an on premise software model. These things include licensing the software, maintenance associated with the software, platform support, and some level of help desk support. One of the main attractions for SaaS customers is simplification – in the cost structure as well as the system management approach.

Cloud Applications is not as specifically defined as SaaS. You see Cloud in various discussion permutations related to platform technology, application technology, deployment strategy, and so on. You could own a Cloud Application, use Cloud Technology to move applications to the Cloud, or any of a number of combinations of options related to public or private clouds.

Hope this helps.