Plastering used to finish architectural constructions, exterior or interior, especially that used for the lining of rooms. Ordinarly, mortar is used for the greater part of the work, and pure plaster of Paris for the moldings and ornaments.

a hardened surface of plaster (as on a wall or ceiling); "there were cracks in the plaster"

Plasterwork refers to construction or ornamentation done with plaster, such as a layer of plaster on an interior wall or plaster decorative moldings on ceilings or walls. The process of creating plasterwork, called plastering, has been used in building construction for centuries.