Students often want to know if they should take the major tests of English as a second language: TOEIC, IELTS and TOEFL. They wonder if it will affect their chance to be admitted to universities or get the job they want.
It's only necessary to take one of the tests if it is required by the university you want to apply for or if it's required by the company you are applying to.
There are other reasons to take the exams, but it's not a necessity. Getting a good score on a test might help give you more confidence, or it might be a goal that you can work towards.
Personally, I don't really believe in testing. Sometimes testing is required and sometimes it may have it's uses, but in general I believe what Glen Doman says: "When testing starts, learning ends." In fact, I dislike testing so much that I got my B.A. degree at an "alternative" university where there are no tests and no grades!
All of the tests do a good job of evaluating your English level. There is no way to cheat the tests. The best strategy is to just learn general English as well as you can. A few months before you will take the exam, study some strategies to help with the test you are going to take.
Here is a very short introduction to TOEFL, IELTS and TOEIC.
The TOEIC test is for people working in an office setting. Studying business English will help you prepare for TOEIC. It is not quite as difficult as IELTS or TOEFL. The TOEIC test is my favorite of the three; I think it is the one to take if you just want to take a test as a personal goal. A TOEIC score might be a good addition to your CV if you are looking for a job and English is your second language.
These days I am teaching at a college in Vietnam that sends students to study in Australia, so I'm teaching some IELTS classes. IELTS is mostly for people who will study or work in Australia. Interpreting graphs and charts is very important for IELTS. It's a little less difficult than TOEFL.
TOEFL and TOEIC are both from the same company, ETS. TOEFL is specifically for people who want to go to a university in the USA. If you don't plan to be a university student in America then you don't need to take the TOEFL test.
To be honest, I really don't like TOEFL- it makes people crazy! It is very, very difficult. It covers a wide variety of subjects at an advanced university level.
I have met many TOEFL students who know a lot of big words but have a lot of trouble with fluency. This why I say it makes people crazy: they think way too much. Most students make the mistake of focusing on the TOEFL exam too soon, before they have acquired any fluency.
The way to prepare for TOEFL, TOEIC or IELTS is to develop your fluency through listening and also read a lot of advanced materials made for native speakers. Read the news every day. Read books, read magazines, read read read. Read magazines like Scientific American or Psychology Today. Read novels. Watch the National Geographic channel and documentary films.
If you read and listen a lot, then your fluency will be growing at the same time as your vocabulary and other skills. Most students just focus on the test, long before they are ready. So in the end they have very little fluency and in fact it's more difficult for them to speak well.
Often it is actually painful to listen to a TOEFL student trying to speak. Their mind is working so hard, they are translating so much with every sentence they try to speak, that what comes out is a stuttering mess. Don't make this mistake!
None of the tests are necessary; check the requirements of the job or university you are applying to.