This lexicon provides information on the fundamentals, practical contexts, and research fields of teaching and learning languages. It includes terms from language, culture, literature, and media didactics, and is particularly relevant for foreign languages in schools in Germany, as well as for German as a foreign and second language. The lexicon offers around 290 articles on the reference sciences of foreign language didactics, various approaches and concepts, competencies, methods, materials, and media, as well as educational policy and institutional frameworks. The individual articles present the current state of discussion and research and also incorporate concrete teaching practices. For the third edition, all entries have been updated and partially extensively revised, and the lexicon has been expanded by about 50 articles on current topics such as education for sustainable development, digitalization and digitality, informal learning, critical foreign language didactics, and language biography.