The main difference between Korean dry jjajangmyeon and regular jjajangmyeon is the thickness of the sauce and how it’s eaten.

    1 ）    Sauce thickness:
       Dry jjajangmyeon: The sauce is drier, less oily, and thicker. It sticks to the noodles without much liquid.
      Regular jjajangmyeon: The sauce is more watery and has some broth, making the noodles and sauce mix together better. It feels more moist when eating.
    2）   How it’s eaten:
       Dry jjajangmyeon: The sauce and noodles are served separately. You mix the sauce with the noodles yourself or dip the noodles into the sauce.
        Regular jjajangmyeon: The sauce is already mixed with the noodles when served, so you can eat it right away.

The flavors are a bit different: dry jjajangmyeon is richer and stronger, while regular jjajangmyeon is better if you like more sauce. Personally, I think dry jjajangmyeon tastes better!