Questions about the tag score, which is calculated once a day for each tag in which you have asked or answered questions.
Your tag score is used to indicate how familiar you are within each tag. It is merely the sum of all the upvotes and downvotes you've received on all of your answers within that tag. Tag scores are heavily cached and only get updated once a day, at 03:00 UTC.
Tag scores are also used when awarding tag badges.