Studies have found that writing notes by hand, if you are listening to a lecture for example, is better than taking notes by using a keyboard on your laptop.
The reason for this is simple.
As you are listening to the speaker you need, if you are writing by hand, to understand what the person is saying as you need to be more economical. For writing by hand is slower and you cannot afford to simply type verbatim what the speaker is saying. You could do this if you were using a laptop or other computer device, provided you were a fast typist, of course.
Writing by hand means you must understand and get to the gist of what you are hearing as you are capturing what is being said more slowly. You must understand and get to the essence of what is being explained.