IELTS is International English Language Testing System, a prerequisite test for admission into universities in many countries like Australia, USA, UK, Ireland, Canada, New Zealand and Switzerland.
It is also a criterion for immigration to Canada, Australia and New Zealand.
IELTS is jointly managed by: University of Cambridge (ESOL Examinations), British Council, IDP Education Australia.
IELTS assesses the language ability of candidates who need to study or work where English is the language of communication.
IELTS measures the four language skills: Listening, Reading , Writing, Speaking
Listening Section
Listening section takes 30 minutes with 40 questions in 4 sections
Ten minutes time is given to transform the answers to an answer sheet
Reading Section
Reading section takes 60 minutes time in which 40 questions are asked based on 3 reading passages with a total of 2,000 to 2,750 words
Writing Section
In the Writing Section you have to write essays of 2 given tasks in 60 min.
Task - 1: You have to write an essay of 150 words in 20 min. 
Task - 2: You have to write an essay of 250 words in 40 min.
Speaking Section
The speaking module consists of an oral interview between the candidate and examiner, which takes 10-15 min.
Test Score
Candidates receive scores on a band scale from 1 to 9 score is reported for each module of the test. The individual module scores are than averaged and rounded to produce an overall band score.
A band score of 5.5-7.0 is necessary for admission into University or College depending on the program.