Technically speaking, yes. TEFL teachers teach English in non-native English speaking countries. TESL teachers teach English in native English speaking countries, and TESOL is the general term to cover all three!
TEFL – ‘Teaching English as a Foreign Language’ certificate, is the most commonly accepted certificate worldwide. This certificate allows you to teach English to non-native speakers across the globe.
TESOL – ‘Teaching English as a Second Language’ aka TESL. Similar to TESOL students, as a TESL teacher, you would likely be teaching English in your home country to students who have moved or live in an English speaking country. In other words, they are continuously surrounded by the language and will be using it everyday outside of the classroom, unlike TEFL students who are likely learning in their home country.
CELTA – Known as the ‘Certificate in English Language Teaching to Adults’ is a very prestigious certification. In order to receive a CELTA, you must complete a 120-hour course along with six hours of observed teaching practice with real ESL students. The majority of CELTA programs are held over four weeks and are full time. However, you may be able to find some courses that are part-time and are spread out over three months. The CELTA program must follow a strict regulation created by Cambridge University.