DM screens, storyteller screens, and Game Master screens are all the same family and same purpose. The screen is there to help create immersion for the players. It separates the DM from them and puts the DM in the role of the person behind the curtain. That’s not all the screen does though, because it really is a Swiss army knife-like aid to the DM. If you look at a DM screen, it comes with a conditions table, and some of them have name generators and basic item prices.