To paraphrase one of the most famous sentences about a democracy: Exams are not the best form of evaluation but it's the best we have. It would be nice to have no exams and be graded fairly. But in real life, each student is responsible for themselves and for preparing themselves for exams. Let's look at the online platforms which can help you with it.
If you are a student, you should have access to special websites designed for your particular university. The most famous Platform, in my opinion, is Blackboard.
It is a very powerful website which gives you an opportunity to repeat materials from your lecturers. Moreover, you can find your mock exams modules, past examination papers and grades which you've already achieved. Sometimes there are links to recorded lectures as well. If you can't use it, you shouldn't resign to only using your university resources, you should ask your lecturers about extra tasks and tips for exams. Most universities have a Students' union or something similar. People who are working there are always willing to help with advice.
Specialist platforms are often hosted by universities, institutes or specialists. If you ask me which are the best for you, I'm afraid I can't tell you. It depends on your modules you are Learning. For people who are studying IT courses, I highly recommend EdX, TED, Codecademy and Khan Academy. EdX is better if you have at least two weeks until the exam as the courses there are complex and it can take you a while before you accomplish anything. If you want to get to know more about your subject, the best choice will be the TED videos which present knowledge in an interesting way.
Codecademy and Khan Academy are the best if you have an exam the very next day and still don't understand part of your studies. A more common source of knowledge is YouTube. You can find there a very wide range of valuable videos, but be aware of keeping a focus on learning. The video below is a great way to have a little break but isn't a great way to acquire knowledge!
You shouldn't limit yourself to only the above-mentioned websites. You can also find a good source of advice on Facebook, forums or even Instagram.
But it is only for "advanced learners" who can separate valuable material from the non-valuable material.
First of all, please, remember that one of the most important tips is to prepare a plan before you start your revising.