Peer voting on questions and answers is the primary way users gain reputation, and also how many items are sorted to the top.
The default sorting option on answers is by vote, with accepted answers by others pinned to the top. Questions in search results, user profiles, and tag pages are also often sorted by vote.
Badges related to the whole act of voting on posts by other users include:
- Supporter - First upvote
- Critic - First downvote
- Civic Duty - Cast at least 300 votes
- Electorate - Of all your votes ever cast, 25% or more have been on questions alone and where you've voted on at 600 questions
- Suffrage - Used all of your 30 votes for a single day
- Sportsmanship - You've upvoted 100 competing answers (i.e. on questions you have also answered)