TEFL is an acronym for Teaching English as a Foreign Language (also known as TESOL - Teaching English to Speakers of Other Languages) and is mostly used when English is being taught in a country where it is not the first language.
As a certified TEFL teacher you will be able to teach English all over the world - or within your country.
TEFL is a relatively easy way to earn good money, experience living and working in another country, or to take a GAP year - and often a great option when looking for ways to fund your studies.