Zoomable User Interface
According to Hornbæk et al. in Navigation Patterns and Usability of Zoomable User Interfaces With and Without an Overview a zoomable user interface (ZUI) is an interface that organizes data objects in space and scale and allows users to interact directly with the information space. Typical interaction techniques of ZUIs are panning (change the visible area of information space) and zooming (control scale of the information space to explore greater levels of detail in the data). Most common is geometric zoom, where the scale linearly determines the apparent size of the object. However, in so-called semantic zooming, often used with maps, some features of the visible objects (e.g. text labels) may preserve their original size while others reveal more details by scaling. In density zooming a constant number of objects is shown, determining the level of detail.