Besides gaining reputation with your questions and answers, you receive badges for being especially helpful. Badges appear on your profile page, flair, and your posts.

Question Badges

Ask a good question on 100 separate days, and maintain a positive question record
4 awarded
Question favorited by 100 users
19 awarded
Question score of 100 or more
21 awarded
Question with 10,000 views
629 awarded

Answer Badges

Edit and answer 500 questions (both actions within 12 hours, answer score > 0)
Answer score of 100 or more
25 awarded
Highest scoring answer that outscored an accepted answer with score of more than 10 by more than 2x
12 awarded
Provide an answer of +20 score to a question of -5 score
1 awarded
Zero score accepted answers: more than 10 and 25% of total
3 awarded

Participation Badges

Visit the site each day for 100 consecutive days. (Days are counted in UTC.)
155 awarded
Earn 200 daily reputation 150 times
1 awarded

Tag Badges

You must have a total score of 1000 in at least 200 non-community wiki answers to achieve this badge.
7 awarded

Moderation Badges

Raise 500 helpful flags
4 awarded
Served as a pro-tem moderator for at least 1 year or through site graduation
4 awarded
Served as an elected moderator for at least 1 year
5 awarded
Complete at least 1,000 review tasks. This badge is awarded once per review type
26 awarded
Edit 500 posts (excluding own or deleted posts and tag edits)
20 awarded
Vote on 600 questions and 25% or more of total votes are on questions
45 awarded

Other Badges

Share a link to a question later visited by 1000 unique IP addresses
4 awarded