Smelts various materials such as iron or copper. The output is a molten material that needs to be sent via molten channel transport, for instance, into a caster for further processing. Molten materials cannot be transported via trucks.
All the cargo that is temporarily stored in the shipyard. When the shipyard gets too full it is unable to unload more cargo from the ship. Trucks always actively remove products from the shipyard whenever there is space somewhere else.
This settlement module has a limit on how many people it can serve. In case the total population of the attached settlement exceeds this limit, you need to build more modules.