Badges are awarded to encourage and reward positive community actions within the site.

For more information, see the [badges] wiki on Meta Stack Exchange.

But note that Stack Apps is a little different from other Stack Exchange sites. See:

  1. Does Stack Apps have some special rep and Community Wiki modifications?
  2. The [meta] tag wiki

Hence the badges here are not fully consistent with other sites. For example:

  1. Stack Apps doesn't have the Beta badge but it does have the API Beta and API Evangelist badges.
  2. Stack Apps currently doesn't have the Informed badge.