Although the concept of scenario utilization is and informal way to determine how the system will be used, with respect to the whole idea and the role it plays in the design process, this results in a more general concept of use cases. The analogy between connection utilization/scenarios and program/thread execution is possible.
In this context, the execution shows a general set of possible actions, while the thread is one instance of this process, so use cases describe a set of viable interactions between the system and the other participants (people, hardware, and so on), while the scenario describes a definitive progression of these interactions. The UML use case diagram describes this thought at a rather general level.