May I know the basic difference between the two? For example, in the case of IELTS are the candidates issues a certification or a certificate? (I think it must be certification, because there's no education/training course provided by the exam administrators.)
A certificate is just to formally declare that a candidate being certified has achieved a certain standard in a subject.
The candidate may have achieved the standard with or without having gone through a course. Of course, going through a course would enhance the chance of the candidate getting the certification.
I am not a teacher.