for DeX users you will find that you can connect a ethernet connection port . while m30 does not supports the DeX. pad you can use a otg that has ethernet cable at other end this will allow you to access the net through cable wire just like a PC does
the wire that comes to your house that provides internet when u plug it into your router or pc is called ethernet cable like GTPL etc. there is a dongle available that you can use to plug that ethernet cable right into your phone to use internet and that's why this option is available to manage it
