Wolgwa-chae is a Korean dish that is made of pickled cucumbers. Pickling is like cooking the cucumbers in a special mixture of vinegar, sugar, salt, and other yummy spices to make them taste different and last for a long time.
Now imagine you have a cucumber that you want to turn into wolgwa-chae. First, you would slice it up into thin pieces. Then, you would mix it with a special sauce made of vinegar, sugar, salt, and spices.
After that, you would leave the cucumber slices in the sauce for a while so that they can soak up all the yummy flavors. This is called marinating.
Once the cucumbers have soaked up all the flavors you can eat them as a delicious side dish or as part of a bigger meal. And that's how you make wolgwa-chae!