Also may I ask how do I setup ssh trust and how do I access the command prompt.
You ask them to deploy a (for example) MongoDB service, they do it, and they are responsible for the operation of it.
The idea is to reduce the amount of day to day (or more likely month to month) work involved in doing things like security patches, upgrading infrastructure, etc, that suck up a lot of time, especially for people who don't have experience in building load balancers and so on.
[1] Cloud Foundry(and by implication AppFog) differentiate apps from services, where services are backend infra like databases.