You can always see your own deleted answers if you visit the page again (except in the few rare occasions of a hard delete). Deletions are by default soft deletions, meaning the content remains, but is invisible to all except
- the owner (in case of answers, not sure about questions)
- users with
>= 10krep - moderators
- developers
Those who can see the content can vote to undelete it. Votes to undelete self-deleted answers by the author are binding, as are moderators' and developers' votes. For ordinary high-rep users, it requires three undelete votes (in general), but moderator-deleted content can only be undeleted by moderators and developers.