In Application there is a single functionality. Single functionality can be done from two places.
(Suppose upload functionality can be performed from Place A and Place B). Since script for upload is same but script for Place A and Place B is different.
I have recorded script for uploading a file from Place A. now i want to reuse it at place B.
You can create reusable code as Custom Keyword
You can call one test case from another using the callTestCase command. Both will allow you to reuse code throughout your project.