Duolingo is a popular language-learning platform that offers free courses in over 30 languages. It uses a gamified approach to make learning fun and interactive, with lessons that include speaking, listening, reading, and writing exercises. Users progress through levels, earning rewards like badges and points for completing lessons. The app is designed for learners of all ages and offers a personalized experience, adapting to the user's pace and skill level. Duolingo is available on both mobile devices and the web, making it accessible anytime, anywhere. The platform also offers a premium subscription, Duolingo Plus, with additional features like offline access.