It can be confusing to know the different greens sometimes because they look the same. Bok Choy and Napa cabbage will have different flavors. Bok Choy will have a more distinct flavor. This means that the leaves will have the tendency to become a bit bitter especially when you would compare them to Napa Cabbage. The stalks of the Bok Choy will also be more fibrous. One thing that you should remember about the Napa Cabbage is that they will take longer to cook as compared to the Bok Choy. You can substitute one for the other but just a lot more time for the Napa Cabbage especially when you are cooking stir fry.
It can be confusing to look at the different greens that are available, but you should realize that knowing the differences will allow you to pick the ones that will work best for your needs. The Napa Cabbage somewhat looks like the Bok Choy, which is one of the reasons why people may get confused between the two. The Napa Cabbage will have a strong earthy taste. It is also darker in color as compared to the Bok Choy. The stalks of the Napa Cabbage are also pale green. The Bok Choy will have a mild flavor though there are some varieties of it that can be a bit strong. Most of the time, the taste will resemble the taste of the usual cabbage.