Indicates the “component” of the city the application/product is supposed to be used in. People “share” common buildings, infrastructures, and services, and follow common action patterns and rules when they live, travel, work, or entertain themselves in the city. The prevalent approach to cities, however, is based on “structural” aspects of cities ranging from air quality through population density to income levels. Undoubtedly, these are important urban aspects; yet, they are largely results of people’s actions and interactions which are guided by needs, desires, rules, and regulations. The framework employed here centers around activities (housing, mobility, etc.) and links them to the corresponding supply systems (buildings, infrastructure, services, etc.).