Interior design is "the art or process of designing the interior decoration of a room or building". An interior designer is someone who coordinates and manages such projects. Interior design is a multifaceted profession that includes conceptual development, communicating with the stakeholders of a project and the management and execution of the design.
In the mid- to late-19th century, interior design services expanded greatly, as the middle class in industrial countries grew in size and prosperity and began to desire the domestic trappings of wealth to cement their new status. Large furniture firms began to branch out into general interior design and management, offering full house furnishings in a variety of styles. This business model flourished from the mid-century to 1914, when this role was increasingly usurped by independent, often amateur, designers. This paved the way for the emergence of the professional interior design in the mid-20th century.