Test Scenario, Test Case and Test data

Test Scenario:

• Test scenarios are the generalized statements describing all the major functions in a module.
• A scenario does not go deeply into a function but it just mentions the function name, its purpose and any major filed restrictions through simple English statements. 
• Only one major function is covered in a scenario.
• Creating scenarios is like splitting the module into a several sub-modules.

Test Case:

• Test case is a simple English statement that checks a small feature of a scenario or a module.
• It would contain steps explaining how to test the feature.
• Test cases are useful because they are repeatable, reproducible under same environment and easy to improve upon feedback.

                                           Typical test case template

Test Data:

• When a test case needs to be checked with various combinations of inputs, instead of randomly giving input while executing the test case, test engineers prepare test data.
• It contains all the possible combinations of inputs
• While writing the test cases itself test engineers prepare test data.