IELTS, British Council and IDP are related.
IELTS was invented by the University of Cambridge, British Council and IDP all together. It so happens that in certain countries British Council is in charge of IELTS exams and in other countries IDP runs IELTS exams, and then there are countries where both British council and IDP offer IELTS exams, which people find confusing and are not sure where to go.
