Sociologists and geographers suggest that the macro patterns of the built environment are formed by the micro interactions of individual, household and business decisions in the interior and the built environment. Interior design activity varies in scale and complexity, from integrated architectural adaptions to the simple positioning of a piece of furniture. Humans are continually redefining the types, styles and forms of interior based on our lives, work and cultures. Many of these alter and adapt to differing patterns of social structure and behaviour. Domestic city interiors can create a certain style or more significantly through the commercial interiors encompassing the other key themes of Leisure, Work, Society, Culture, Retail Health and Home interiors. While the discipline themes can be continually subdivided into specialist subsets, agencies usually group their practices around one of the main typology themes discussed below or specific staff specialisms, or possibly regional traits and their client base.