a use case is a technique for capturing the potential requirements of a new system or software change. Each use case provides one or more scenarios that convey how the system should interact with the end user or another system to achieve a specific business goal.
a test case is basically a set of conditions applied to an application to see if it meets the requirements or not.
You're new here... Let give you a few hints on posting for success ...
First the original poster was asked by the first respondent if they did a search and what they found out.
This is the FIRST action that should be done before posting - it is even stated on the Posting Guidelines in the FAQ:
1) Please execute a search regarding the potential topic you are considering posting (located in the upper right corner). There are hundreds of threads on various topics that may answer your question existing in the archives. Topics posted which already exist in the archives will be removed without explanation.
<font size="2" face="Verdana, Arial, Helvetica">The second response requested clarification - another attempt to have the original poster think it out for themselves, starting a dialog.
YOUR response did "spoon feeding" of an answer instead of adding to a conversation.
That doesn't help A)the original poster learn or B)the forum as a whole.
Please do a search for "use case" - there are several discussions of this already on the forum.
If you had really wanted to help Kanatha, you would have suggested he look it up in the Wikipedia, like you did. Also if you quote another source word for word, please give credit to the original source. http://en.wikipedia.org/wiki/Use_case
Success is the ability to go from one failure to another with no loss of enthusiasm.
~ Winston Churchill ~
No one said your the bad guy. kantha could have done exactley what you did, why do you think he didn't ? What we are looking for here are independent/personal views, not material already on the net. We can all search google, but something written from experience is of more value here.