There are two categories of badges:
- Site badges. Available to users site-wide and related to the site wide activities, like finishing a set of courses. They are created from 'Site administration>Badges>Manage badges' section.
- Course badges. Available to users enrolled in the course and related to the activities that happen inside the course. They are created from 'Administration>Course administration>Badges>Managing badges', inside a course.
You'll find more information about how to manage course badges on the following page: https://docs.moodle.org/35/en/Managing_badges#Managing_course_badges