Digital Badges or Micro Credentials are small rewards given to students for mastering a skill, completing a task or good behavior. Badges are often an element of gamification. Some teachers assign students XP (experience points) based on classroom activites and award badges when certain XP thresholds are met enabling students to "level up" in class.
Many digital learning tools have badge options built in such as Moodle, Canvas, Schoology, and Power School LMS. Or use a standalone badge tool such as Open Badges and Class Craft.