keydown
keydown is the moment when your fingers press the keyboard,
and all kind of keyboard button has correspondent keycode.
Once you press the button without releasing it, it will keep triggering the event continuously.
keypress
Similar to keydown event, but with different target.
Keypress focus on buttons which can output text and symbol.
keyup
keyup is the moment when your finger leave the keyboard button, and there won’t be continuous triggering since it only happens once.
Triggering sequence
keydown => keypress => keyup