Why would professors give online tests that aren’t moderated or watched? Now, I understand that cheating is wrong, but if the test is online, then is it just an open note/book test? IMO, I think it has to do with taking good notes in class, and then using your notes for the online test.
Sometimes what amounts to Open Book tests are the hardest- b/c it isn’t about a narrow, specific answer, but about a analysis, context, process, etc. In some STEM subjects you are allowed to bring formulas into a test room with you- b/c the prof knows that what matters is that you know when & how to use which ones. Some tests cheating is actually harder than the work you would have to do to actually learn it. And some tests are a way for the prof to make sure that certain information has actually passed through your brain - enhanced studying techniques 
Are you a first year university student?
I’m a junior in college, but I’ve always found online quizzes/tests easier than actually studying for real.
Interesting. If it was first year 101-type classes I would be less surprised, but third year classes where the answers are simple right-wrong facts is unusual ime.