School lunches in Korea (and much of Asia) always seem to be served in these specialised metal trays. The smaller deeper bowls at the top are for your side dishes, or banchan (반찬), while the shallower, more central indentation is meant for the main dish. The usages of these three receptacles do seem to be somewhat interchangeable however - particularly if the main course is saucy or there is a flat side or dessert served.
The lower two bowls are reserved for rice and soup. The rice is always placed on the left and the soup on the right. Don't mix these up, you will get a ridiculously large number of strange looks if you do! (And this from people who didn't flinch when I started photographing my lunches!). As with all Korean meals, you are also given a spoon and chopsticks. The spoon is for both the soup and rice, while the chopsticks are for everything else. Eating your rice with chopsticks will garner you looks just as strange as if you'd put your soup in the wrong bowl.
Both rice and soup are present at every meal (even when I don't take any as the main dish is noodle based as above). The rice is left plain so that you can used it too soothe your poor tongue should any of the other food prove to be too spicy (as is often the case - though I am also partial to mixing my sides into my rice). The soup can also be used to serve this important function. It's mainly there for another reason however, Koreans don't believe in drinking water while eating! (Though they do believe in drinking alcohol... hmm...) This is so that you have space in your stomach for food. Water is often drunk after the meal. I don't know about you, but personally, I get thirsty when I eat!
Another element which is present at every meal is kimchi (김치), or fermented cabbage dressed in spicy chili sauce. While I don't necessarily add it to my dish every time, a number of the other teachers will fill their banchan bowls to overflowing with kimchi (and look curiously at me when I don't - similarly, they always say I don't take enough rice!). If you look carefully at the upper right hand bowl two pictures above, you'll notice that I not only had normal cabbage kimchi, but kkadugi (깍두기 김치), or cubed radish, kimchi as well.