Is this soup, stew, or something else?
It's a hot pot or steamboat as we call it in Malaysia. It's a clear soup made from stock. Raw ingredients are gradually added to it as it simmers. Soup and the cooked ingredients are fished out when they are done (each time when the pot boils). At the end, you are left with a rich, delicious soup that has flavours of all the ingredients intermingled and it is usually eaten with noodles.

Going by this, it would be classified as a soup or broth. It wouldn't be a stew as flour has not been used to thicken it.