Badges are a creative way students can show evidence of their learning separate from the grade-obsessed culture our school system has found itself so attached to. There is a plethora of research as to why grades are an inadequate and harmful way to measure student learning. Grades create risk-adverse behavior, demoralization, and tell us little about a students actual capabilities. Most tragically, grades create an end goal of learning. According to our current system of measuring progress, once a student has accomplished an "A" or specific grade, they have conquered and mastered the topic. However, we know that learning is never-ending. It is a quest. It is a life long journey. There is no "end goal" in learning, except perhaps growth and development. (Check out this article to delve deeper into this topic.)
Badges are a way to remove this "end goal" on learning. They are a way to encourage students to pursue their own learning, at their own level, and to never stop progressing. They celebrate students for what they can do, not for what they cannot do. Badges are awarded based on level (apprentice, developer, trailblazer), soft-skills (such as empathy, collaboration, leadership), or content knowledge. They show progress, accomplishments, successes, and personal development. They encourage risk-taking, creativity, positive personal characteristics, and construction of personal knowledge. They can be shown off to fellow students, families, and teachers and linked to the work that earned them their badge. Most importantly, badges are a way to differentiate learning for students of all abilities.
To read more about badges, and gamification of learning, check out these articles;