Staging is the placement of the characters within a set. The characters have to be part of the composition of the whole image and their placement in relation to each other has to work. If the characters are moving, a choreographed movement has to be planned. For dialogue scenes, precise camera angles and cuts have to be prepared and the direction of the light and corresponding shadows defined in floor plans.
All this is not the sole responsibility of the production designer; the director also decides about these issues, but you have to come up with ideas and you have to know about all the technical details.
It is very important to create ...