The International English Language Testing System (IELTS) is used to assess language ability in four language skills (reading, writing, speaking and listening).
An IELTS certificate is usually required for study or work in the UK (as well as some other English speaking countries) for entry or visa purposes.
If you would like to improve your English skills more before you prepare for your IELTS exam, you can combine the IELTS course with an English Language Skills course.