Linguistic diversity is part of Europe's DNA. It embraces not only the official languages of Member States, but also the regional and/or minority languages spoken for centuries on European territory, as well as the languages brought by the various waves of migrants. The coexistence of this variety of languages constitutes an asset, but it is also a challenge for Europe. This fourth edition of "Key Data on Teaching Languages at School in Europe" describes the main policies on the teaching and learning of languages, with a focus on foreign languages. It contains 60 indicators in five chapters entitled: Context, Organisation, Participation, Teachers and Teaching Processes. A variety of sources were used to build the indicators, and these include the Eurydice Network, Eurostat, and the the Organisation for Economic Co-operation and Development's (OECD's) Programme for International Student Assessment (PISA) and Teaching and Learning International Survey (TALIS) international surveys. Eurydice data cover all countries of the European Union as well as Bosnia and Herzegovina, Switzerland, Iceland, Liechtenstein, Montenegro, the former Yugoslav Republic of Macedonia, Norway, Serbia and Turkey. While this book builds on the previous edition published in 2012 (see ED539383), it also investigates new areas, principally the language provision for children from migrant backgrounds. The report was produced in close cooperation with the European Commission. The main findings of the report are summarised at the beginning of the publication. The codes, abbreviations and acronyms used are also listed at the front, while the glossary appears towards the end of the volume together with a short bibliography. These are followed by three annexes, which include short country descriptions of foreign language provision, information on the provision of Content and Language Integrated Learning (CLIL) and detailed statistical data.