This tag refers to all questions deleted from Stack Exchange sites. You can also use this tag along with [specific-question] and [meta] to ask why a specific question on Meta Stack Exchange was deleted.
The tag deleted-questions refers to all questions deleted from Stack Exchange sites. The tags specific-question and meta should also be used when referencing a specific question that has been deleted on Meta Stack Exchange. (If you want to ask about a deleted question on another site, ask on its per-site meta.)
For more information on what deletion is, see How does deleting work? What can cause a post to be deleted, and what does that actually mean? What are the criteria for deletion?
If you want to find your deleted questions you can use this link (which will load the pages for the currently logged-in user).