TEFL stands for Teaching English as a Foreign Language, and traditionally refers to teaching in non-English speaking countries. TESL stands for Teaching English as a Second Language and refers to teaching in English speaking countries, to non-native speakers living or working there. In practice, the acronyms TEFL and TESL are often used interchangeably, and both are covered by the all-encompassing TESOL, which stands for Teaching English to Speakers of Other Languages.