Peer voting on questions and answers is the primary way users gain reputation, and also how many items are sorted to the top.
Voting relates to many a splendid base of the default sorting option on answers.
Badges related to the whole act of voting on posts by other users include:
- Supporter - First up vote
- Critic - First down vote
- Civic Duty - Cast at least 300 votes
- Electorate - Of all your votes ever cast, 25% or more have been on questions alone and you've voted on at least 600 questions
- Suffrage - Used 30 votes in a single day
- Vox Populi - Spent the maximum of 40 votes in a single day
- Sportsmanship - You've upvoted 100 competing answers on questions you have provided an upvoted answer to
Copied from: http://meta.stackexchange.com/tags/voting/info