There have been well-publicised studies showing that we remember more when we take notes by hand than by typing them on a computer.
Mueller and Oppenheimer, The pen is mightier than the keyboard: Advantages of longhand over laptop note taking, 2014
The explanation is that we can type faster than we can write, so when we take notes (while listening to a lecture, for example), we’re more able to capture things verbatim. Whereas, when we write by hand, we have to reformulate and condense the concepts in order to be able to keep up. And in doing this, we engage more deeply with the concepts and therefore understand and remember them better.
However, there has been mixed subsequent evidence to support any clear advice that students are definitely better off taking notes by hand. In fact, a more recent study by Morehead, Dunlosky, and Rawson found no significant difference, especially after a couple of days.
The conclusion, for now, is that while making notes is valuable and should be encouraged, students should do this in whatever way is most convenient for them.