IELTS is an acronym for “International English Language Testing System“. The IELTS test is also a test of an individual’s ability to use and understand the English language. There are two versions of the IELTS: the Academic Version and the General Training Version. The Academic Version is similar to the TOEFL in that it is intended to provide information about an individual’s ability to understand English for an academic or school setting. The General Training Version of the IELTS is used to assess English language proficiency for people who need English for work or immigration reasons. The IELTS is used frequently in Australia, Great Britain, Canada, Ireland, New Zealand and South Africa. The Academic Version is also accepted at many American universities although the TOEFL remains more prominent. Obtaining a passing score on the IELTS is required for immigration to Australia, New Zealand, and Canada.
The IELTS looks at 4 areas of language: reading, listening, speaking, and writing. Each of these areas is tested for a specific amount of time (11-60 minutes depending on the domain). All but the speaking module must be taken in the same day, the speaking domain or module must be taken within 7 days of the other domains. IELTS scores range from 0-9. Each number score also corresponds to competence level; for example 9 = Expert User, 6 = Competent User, and 1 = Non User. The minimum score needed on the IELTS Academic Version for college admission in America varies from college to college, but usually a score of 6 is the minimum. When the IELTS is used for the purposes of immigration, required scores generally vary as well, with a minimum of 5 required by New Zealand and a minimum of 6 required for Australia in order to immigrate.
Gaining a strong understanding of the English language is required before taking either of these exams. St. Louis recommends a minimum of CLB Level 6 in order to achieve success.
(Excerpts of this explanation have been taken from http://blogs.transparent.com/english/tofel-and-ielts-what-do-i-need-to-know/ )