What does "Special Use Airspace" mean?

Special Use Airspace refers to airspaces that are used for activities that must be confined within the airspace because of the nature of these activities and limitations are imposed on aircraft operations that are not part or participating in such activities.

There are six special use airspaces, this include:
Restricted areas, Military Operations Area (MOA), Warning areas, Prohibited areas and controlled firing areas.
Of all the six special use airspaces, only controlled firing areas are uncharted and there is no controlling agency to contact to fly across controlled firing areas.