I know Duplication is a bit of a contentious topic so I've looked around before asking this, but I can't find an answer. If I've missed it I'd appreciate being pointed in the right direction.
What does Closing a Question as a duplicate actually do? Particularly in the circumstance where different Questions lead to duplicate Answers. For example Hyperion Duplicate is closed as a Duplicate, but it obviously still exists on the site, a search for keywords in the Duplicate question still brings it back. I can still vote on duplicates (sorry if that's spammy).
If someone else wants to find the Hyperion books and only remembers the Dolphin planet, is there a time limit on how long they'll be able to find the answer via this duplicate, or will they generally have to wade further through search results than they might without the marking?
The only functional difference I've found is that I don't appear to be able to add an Answer, but obviously in the case linked above there would be no way to tell they were duplicates without Answers on both already, because there's no overlap in the Question text.
Looking at the tags in meta I might be confusing some properties of Close and Duplicate which appear to be separate processes.