The biggest difference is flexibility. Loose-leaf notebook because loose-leaf can be inserted freely, so it is convenient to arrange and supplement at any time, but also homemade. If you want to sort it, you can split it up quickly. Carry a few or dozens of pieces, at will. But loose-leaf books are heavier because of the loose-leaf buckle.
Ordinary notepad if you want to insert a new record in the middle, it is more troublesome, such as adding paper, stickers, etc., easy to drop and not neat.