Rote learning
Rote learning means memorizing something by repeating it over and over until it sticks, without really understanding it. It works okay for a small set of facts you just need to recall, but it falls apart the moment you have to apply or explain the idea.
The repeating part actually does work for raw facts. Dates, formulas, vocab, the order of the planets, stuff where you just need the answer to pop into your head. Your brain learns the pattern through sheer repetition, and that's fine for a quick lookup.
The problem shows up the second a question asks you to use the thing instead of just spit it back. If you only memorized the words and not what they mean, you freeze on anything worded differently from how you drilled it. A common mistake is reading your notes ten times and calling that studying. You recognize the page, so you feel ready, but recognizing is not the same as being able to recall it cold or explain why it's true.
Maria memorizes the quadratic formula by writing it out 20 times the night before her math test. She can recite it perfectly. Then the exam asks her to explain when to use it instead of factoring, and she's stuck, because she never learned what it was actually for.