Khan Academy is a free online learning platform where students work through practice exercises, and this short chime is the feedback sound played when a task is marked complete. Because millions of students heard it while doing schoolwork, it became instantly recognisable outside the classroom and started appearing in memes about homework, studying, and finishing something difficult. Creators now reuse it as shorthand for academic success and relief, which keeps it popular in study videos, school jokes, and productivity content long after learners leave the platform.