It is a test of English Language proficiency. It is jointly managed by university of Cambridge ESOL Examinations, the British Council and IDP Education Australia.
There are two versions of the IELTS: The Academic Version and the General Version.
The Academic Version is intended for those who want to enroll in universities and other institutions of higher education and for professionals such as medical professionals and nurses who want to study or practice.
The General Training Version is intended for those planning to undertake non-academic training or employment, for immigration purposes.
IELTS is accepted by almost all Australian, British, Canadian, Irish, New Zealand and more than 1800 US academic institutions. It is the only acceptable English test for immigration to Australian and also accepted by UK and Canada.