What is is the difference between TEFL, TESOL, CELTA and TESL?

What do the abbreviations TEFL, TESOL, CELTA and TESL stand for?

• TEFL stands for Teaching English as a Foreign Language
• TESOL stands for Teaching English to Speakers of Other Languages
• CELTA stands for Certificate of English Language Teaching to Adults
• TESL stands for Teaching English as a Second Language

What is the difference between these TEFL, TESOL, CELTA and TESL certificates?

• In practice, the difference between these courses is relatively small. The target group for the courses are people who want to improve their English skills
• In many countries a teaching skills certificate is requested, this can be TEFL, TESL, TESOL or CELTA.
• TESL is a course that fits best to people who want to teach English to foreigners in an English-speaking country
• TESOL tends to include practical English skills that help learners adjust to life in an English-speaking environment but is generally seen as broader in scope then the TESL course
• The TEFL course is mainly preparing students to teach English in countries where the first language isn't English.
• The CELTA certificate always contains practical teaching training and is an internationally recognized qualification that usually ranks above the other three certificates.