FluentU is an online language learning platform that uses real-world videos, such as movie trailers, music videos, and interviews, to teach languages. It offers interactive subtitles, allowing users to click on words for definitions and example sentences, enhancing vocabulary and comprehension. The platform supports various languages, including Spanish, French, Chinese, and German. Users can track their progress through personalized quizzes and flashcards, making it suitable for learners of all levels. FluentU aims to create an immersive learning experience that helps users engage with the language in a practical context.