Maps and scenes
GIS content can be displayed in 2D or 3D views, and there are a lot of similarities between the two modes. For example, both contain GIS layers, both have spatial references, and both support GIS operations such as selection, analysis, and editing.
However, there are also many differences. At the layer level, telephone poles might be shown in 2D as brown circles, while the same content in 3D could be shown as volumetric models—complete with cross members and even wires—that have been sized and rotated into place. At the scene level, there are properties that wouldn’t make sense in 2D, such as the need for a ground surface mesh, the existence of an illumination source, and atmospheric effects such as fog.
In ArcGIS, we refer to 2D as “maps” and 3D as “scenes.”