Say a user asked a question. He had answers on it, as well as upvotes and downvotes, but then his account is deleted for some reason. What will happen to all the questions, answers, upvotes and downvotes?
When a user is deleted, all questions/answers except downvoted ones are kept.
When a user is destroyed, the account and all posts are deleted. This is usually for spammers.
The votes get removed in both cases, and affected users will see a
-xyz User was removed entry in their reputation history.