In 1938, Louis Wirth's concept of "Urbanism as a Way of Life" refers to the distinctive social and cultural characteristics of urban areas that distinguish them from rural areas. Wirth argued that the qualities of urban life arise from the interplay of three key factors: size of settlement, density, and heterogeneity.

1. Size of settlement, refers to the scale of urban areas, which tends to be much larger than rural settlements. This larger scale results in greater social competition for resources and opportunities, which can lead to greater individualism and social mobility.

2. Density, refers to the concentration of people in urban areas, which leads to greater social interaction, but also to greater differentiation and conflict among different groups.

3. Heterogeneity, refers to the diversity of people and cultures within urban areas, which can lead to new forms of group formation and social innovation.