A Digital Twin generally refers to a 3D model of a physical construct of a building, machinery, or a city. It usually includes an informational overlay powered and augmented by data updates from installed sensors and other data points.
An Urban Digital Twin is a 3D virtual replica of the real-world built environment, connected to massive amounts of data and software tools. This has almost limitless capabilities and development potential. Some examples of data overlays include Historical and Cultural site locations and information, real-time traffic monitoring, parking availability monitoring, temperature and airflow metrics, CCTV connectivity and feed overlays, simulations for solar radiation studies, shadow analysis, rainfall, floods and more.