Jang 장 refers to Korean traditional condiments such as ganjang (soy sauce), gochujang (red chili paste) and doenjang (soybean paste).
And Jangajji 장아찌 are pickles whether it's done with just salt, vinegar and sugar or more traditionally made with soy sauce, sugar and vinegar. Cucumber and Garlic Scape Pickles are my classic Jangajji recipe, you can also make Pickled Perilla leaves (Kkaennip Jangajji) which is great with Korean BBQ.
Both are left to ferment or pickle and will keep preserved for months so in that sense they belong together.