English as a Second Language (ESL) differs from EFL, in that ESL implies the teaching and learning of English in an English-speaking region (e.g., the US), while EFL more commonly applies in non-English speaking regions. EFL and ESL involve different challenges and strategies for teachers and learners alike.
Teaching English to Speakers of Other Languages (TESOL) and Teaching English as a Foreign Language (TEFL) are often used as interchangeable terms. While they differ slightly from one another, both are established, internationally recognized standards for methodology and practice to teach English language skills to non-native-English speakers. TESOL certification is widely regarded as a rigorous standard for teachers, and requires prescribed curriculum, and a minimum six hours of supervised practice teaching in an actual student-classroom environment. A TESOL certificate is widely recognized by EFL teaching schools and programs as the mark of a well trained, highly qualified EFL teacher. Because there are so many TESOL training programs to choose from, Teaching Nomad has made it easy for you by partnering with Global English, an Internationally accredited TESOL training program. You can learn more about them here.
On the student side, the Test Of English as a Foreign Language (TOEFL) is a widely recognized test of proficiency in the English language. At most US and U.K. colleges and universities, a verifiable passing mark on the TOEFL exam is a requirement to matriculate for all students from non-English-speaking countries.