I don't understand the difference between downvoting a queston, and vote to close it. Specifically, what causes less damage?
There is a lot of detailed information from the help pages for Stack Overflow regarding privileges:
These guidelines are valid all over the Stackexchange network with only little variation amongst specialized sites.
In summary we may vote down questions or answers for the following reasons:
- Use your downvotes whenever you encounter an egregiously sloppy, no-effort-expended post, or an answer that is clearly and perhaps dangerously incorrect.
- Voting down answers is not something we want you to take lightly.
- Downvoting should be reserved for extreme cases. It's not meant as a substitute for communication and editing.
We mainly use our close votes for the following reasons:
- Questions that are sufficiently off-topic, as outlined in the help center.
- Questions that are sufficiently similar to older questions.
Whenever we cast a close vote we will see a tick box from where we can choose additional reasons why we believe this question should be closed:
See also the following SO Meta questions on recent changes to the close voting system:
- Closing changes: on hold, unclear, too broad, opinion-based, off-topic reasons, bye-bye to Too Localized
- What is a "closed", “on hold”, or "duplicate" question?
Please also read the following meta post here to get an idea why we should not downvote:
When to use which?
Both votes have considerable overlap. In fact a downvote will automatically be added to a question closed for any reason except putting on hold or duplicates. Therefore we may use both our votes if applicable, or only one of both.
Note that whenever we had closed a question no answer can be added and it will take more effort to reopen it again.
Please also take in consideration that whenever we had downvoted a post for any reason we should go back to the question to see if it was edited. In case the downvote reason had disappeared please undo the downvote (or even upvote when the post was good after the edit). This sadly does not happen too often.
A word on spam
Answers or questions which are spam as outlined here:
Should not be edited to better keep track on the spammers. Also downvotes or close votes are of little use. We should immediately flag them as spam instead. This will also automatically add a downvote. Only if we do so we will be moderately fast enough to destroy the post be it through moderator action, or automatically through the community after enough flags were gathered.
Questions which are ambiguous should be closed until they are clarified, because closing them will prevent premature answers.
Sometimes people will provide otherwise good answers and be angry to sacrifice them, if the question is abandoned later, closed or reworded.
Closing a question seems to be a hard way to interact with persons, but it often means less harm in the long run.
If you hover your mouse over the down button, you see a tooltip:
This question doesn't show any research effort; it is unclear or not useful.
In contrast to Takkat I say: If a question matches this criteria, take it easy. It isn't your fault if the question is unclear, useless or sloppy and the button isn't there for reasons of symmetry.