CELTA is a very similar teacher training qualification to the CertTESOL,

accredited by Cambridge ESOL. Although similar in its content, the two courses
differ in terms of more specific components and types of assessment. Trinity
lays great emphasis on reflective journal writing, professional development and
self-evaluation for trainees. Importantly, both courses are internationally
recognised and accepted by the British Council as initial qualifications for
teachers in its accredited institutions in the UK and overseas. Both are
accredited on the UK Qualifications Framework at level 5.

‘TEFL’ stands for ‘Teaching English as a Foreign Language’. It is a generic
term that can be used to describe the whole profession and industry. Sometimes
non-accredited courses – such as some online and weekend courses – are
described as ‘TEFL’ courses. While these courses can be useful as a brief
introduction to the profession, as they are unaccredited they can vary greatly
in content and quality. It is important to note that many schools and teaching
centres will not accept these as a teaching qualification.