In HBT, a test scenario is one that validates “a-behaviour’ of an entity under test. Given that the behaviour can be modeled as a set of conditions to be satisfied by an EUT, a scenario represents an instantiation of the values of all the conditions resulting in a flow.
A test scenario with at least one condition violated is termed as “negative scenario”, while a positive scenario is one where none of the conditions are violated.
A test case is a combination of inputs and represents a data set. A test scenario is thus a collection of test cases. The objective of positive test cases is “conformance” while the objective of negative test cases is “robustness”.
That is scenario is a path or flow of a given behaviour while a test case is a combination of data (stimuli) that makes the system take that path.