The first one is TEFL certificate, that is Teaching English as a foreign language. It’s an international English language teaching certificate, originated in the United Kingdom. It is authorized Jointly by the university of Washington and the university of Cambridge. An international English teacher training center, organized by many famous universities is responsible for academic supervision and management of English teacher training program.
The second one is TESOL. That is Teaching English to Speakers of Other Languages. It is originated in the United States. Its theme is to discuss English teaching methods and the TESOL courses.Through assessment examination and appraisal, you can get this international recognition of TESOL English teacher qualification certificate. TESOL courses has been recoginized by 8000schools in over 100 countries in the world, and has more than 14000 professionals.In North America, Britain, Australia, New Zealand,ect. It is fully recognized.TESOL certificate covers the TEFL certificate courses.Its authority is widely accepted.
The third one is CELTA, namely Certificate in English Language Teaching to Adults. For those with little or no experience in teaching, CELTA is the first qualificationto enter into the esl jobs field.CELTA is not only in Britain and TESOL certificate.At present, many global institutions engaged in language teaching admit CELTA certificate. The certificate has been listed in the national curriculum standards.