ELT: English Language Teaching/Training
TEFL: Teaching English as a Foreign Language
TESL: Teaching English as a Second Language (e.g. to immigrants)
TESOL: Teaching English to Speakers of Other Languages (more or less the same as TEFL, but can include TESL as well)
Cambridge CELTA: A widely recognised Certificate in English Language Teaching to Adults which is gained from a 4- or 5-week Intensive course.
Trinity Certificate in TESOL: A widely recognised certificate which is gained from a 4-week intensive course.
Cambridge DELTA: A much more advanced diploma for experienced teachers which includes an exam consisting of observed lessons and written papers.
Trinity Diploma in TESOL: A much more advanced diploma for experienced teachers which includes an exam consisting of observed lessons and written papers.
British Council: The organisation which runs a voluntary quality assurance scheme (the English in Britain Accreditation Scheme) in the UK. Members of the Scheme have a continuing obligation to work to the agreed standards. Most year-round schools are members of the scheme, and are re-inspected every four years.