MIDI keyboard with Nord electro 6d

Hi everyone,
New here :slight_smile:
I’m trying to figure out a few things:

  1. What will be the advantages of connecting a midi keyboard to my Nord electro 6d or my cobalt 8x?
  2. Must I connect them via a 5 pin midi cable or can I use a USB cable?
  3. What are the advantages of connecting the cobalt to my nord 6d?
    Thanks!