The IELTS (International English Language Testing System) is a test of English proficiency. The IELTS General Test is primarily for immigration and work permits while the IELTS Academic Testi is used mostly for admission to masters programs at universities .
Both versions of the IELTS are nearly 3 hours in duration and test the four skills of Reading, Writing, Listening, and Speaking.
IELTS is widely accepted across countries and is mandatory in quite a few (UK, Canada, Australia, New Zealand).
You can take the IELTS on designated dates only. The test is conducted up to 48 times every year.