Sometimes in a marked block of text we want to change the name of variables or objects, of course we can always use search/replace. But there is a better alternative, rename as you type and swap all occurrences within the selection. As it is harder to explain than to show, so watch the video and learn:
Use this feature whenever you want to rename an object within a selected block, never use this feature for an entire unit, for this case you should use the refactoring that the IDE has.