Difference Between Ariba Cloud and On-Premise

Please can somebody tell me the difference between Ariba cloud and On premise, I have been working on On-Premise for about 5 years and I got the project on Cloud, I cannot find some screen I am used to and when I ask I keep getting the answer not available on cloud.

The Consultant I am working with is not an Ariba Functional Consultant, he is more of the Programming side. I am getting confused.

Please can somebody point me to the different screens.

Thanks

Enobong