Cramming
Cramming means studying a big pile of material in one long session right before a test, usually the night before. It can get you through the next day, but you forget most of it fast. Spreading the same hours over several days works far better.
Cramming feels productive because you cover a lot in one sitting and the facts are fresh the next morning. The problem shows up a few days later. Your brain treats stuff it sees once as not worth keeping, so most of it drains away after the test. Cramming gets you a grade, not real learning.
The fix is boring but it works. Take the same total hours and split them across several days. Seeing something on Monday, then again Wednesday, then Friday locks it in way better than five hours in a row on Thursday night. This is called spacing, and the research on it is about as solid as study advice gets. The common mistake is thinking that one giant session equals three small ones. It doesn't, even if the clock says the same number.
Maya has a biology test on Friday. Instead of pulling an all-nighter Thursday, she does 40 minutes Monday, Tuesday, and Wednesday on the same chapters. By Friday the cell cycle stuff actually sticks, and she still remembers it the next week.