courses, from Python to HTML, SQL, C++, and more, in Duolingo-style bite-sized lessons. It also hosts a mobile code compiler as well as community interaction support such as user comments on Lessons, coding challenges, and a Leaderboard with over 29 million users. A course is made up of modules and lessons that split topics into smaller groups, and each lesson combines theory with quizzes and practice. Most modules and courses include an overarching code project that users complete little by little as they learn the corresponding topic.