Use Case is written in Business Design Document(BDD)by the Business Analyst.It is for understanding the functionality for the person who is involved in writing the testcases.
USE CASE EXAMPLEAction Response when OK button is clicked Screen 1 appears
Testcase is different perceptions for a functionality to be tested.Usually written by Test Enginneer.The same person who has written the testcase may execute them or the other person
Above Usecase is converted into TestCase keeping in mind different perceptions(-ve and +ve)
Action Expected Value Actual Value Result click on Ok screen 1 should appear(+ve perception) screen1 appeared pass click on ok screen 2 should appear(-ve perception) screen 1 appeared fail click on ok screen 2 should appear(-ve perception screen 2 appeared pass
Difference between test case and use case is use case is prepared by High Level Management team but test case is prepared by Test engineers. Use case is prepared for validating the applications in terms of Actors, actions and responses but test case is used to test a specific functionality of an app
use case is description of series of events that occur between user and system. i.e. how system will response when a particular action is taken by user.
Test case:-in use case a generalised scenario is given.but in testcase we are more throughly testing the various aspect of that generalised scenario.
In an application if i enter the delete button it should give an error msg "Are u sure u want to delete" but the application gives the message as "Are u sure". is it a bug. And if it is how would you rate its severity.