Let’s tackle the differences:
TESOL and TEFL clearly look different, and that’s because they describe the term of teaching English to non-speakers differently.
You either study TEFL or TESOL depending on if the country where you study it is an English speaking country or not. Additionally, you'll learn TESOL if you're in Australia and the US and TEFL is used in the UK.
We admit, it can be pretty confusing. To make it a bit easier, we'll briefly explain some of the history.
Generally there are two main schools of English study:
ESL = English as a Second Language
EFL = English as a Foreign Language
Learners of English as a Second Language are those who need to speak English every day because they live an English speaking country. Learners of English as a Foreign Language only learn English for their hobbies, travels, or business. They don’t have to use English on a daily basis.
Moving back to TESOL and TEFL. It’s clear why it is called TEFL – it’s Teaching EFL. Why then is there a difference in TESOL? There were Australian professionals who felt that English as a Second Language was demeaning and not exactly descriptive. They changed the acronym to TESOL – focusing more on the person learning English rather than the function of their learning. TESOL – Teaching English to Speakers of Other Languages – is much more descriptive and easily can apply to those learning English as a pastime, or because they need it on a day-to-day basis because they live in an English speaking country.
It all seems a little confusing, doesn’t it? The most important thing to keep in mind is that TEFL and TESOL training refer to the exact same thing! A TEFL certificate or a TESOL certificate will both give you the qualification you need to teach English overseas.