IELTS, the acronym for the English Language Testing System, is an English-proficiency exam primarily designed for those who wish to work or study in the United Kingdom and the British Commonwealth countries, including Canada, Australia, and New Zealand. It’s the preferred exam for those destinations, but some of the British Commonwealth countries are now also using or about to use United States-based English proficiency tests. In particular, for student visa purposes, Australia now also uses the TOEFL (Test of English as a Foreign Language) and will also be using the Pearson Test of English Academic (PTE Academic) later in 2011.
To be sure of the English-proficiency test you need to review for, check with the company or school in the foreign country of your choice.