well this is a very  interesting  question  because when  i think of the  national  currency as the moment, what comes to my mind  is the US dollar because I have  been to many countries  and it is  no problem to  go there  and then exchange i to the national currency. when I think of digital currency of course bitcoin comes  to my  mind, and I guess it is  the same case  for many other people when they think about the digital currency because bitcoin in all discussions and memes and advertisements are being used as the image  to present  all other types of digital currencies   .