What is the difference between TEFL and TESL?
Actually, not much. TEFL stands for Teaching English as a Foreign Language and TESL stands for Teaching English as a Second Language. EFL is more of a British term and ESL is an American term. Beyond that, a distinction is made between teaching English to non-native speakers in a non-English speaking country (EFL) and teaching English to non-native speakers in an English-speaking country (ESL). This distinction is not observed consistently. Some British teachers use EFL (TEFL) as a blanket term whereas many American teachers use ESL (TESL) as a blanket term. The same applies to TEFL and TESL. (ESL ignores the fact that learners may well be on their third, fourth, fifth or sixth language. EFL, some people contend on purely pedagogical grounds, should stand for English as a First Language!). In short, teachers holding TESL certificates are generally considered qualified to teach TEFL and teachers with TEFL certificates are usually deemed to have the qualifications to teach TESL.
