Digital twin
also: virtual model · plant model · simulation model
A software model of a physical product, system or building kept in step with real data, used to simulate, monitor, predict and optimize its behavior.
The term covers a range: from a physics-based simulation used to design and test controls, to a live model fed by telemetry that estimates hidden states, predicts failures or tests "what if" scenarios before changing the real system. In buildings and energy, twins model thermal behavior to improve HVAC control; for machines, they predict wear and support maintenance planning.
A twin is only valuable if it is accurate enough for its purpose and maintained as the real system changes. System identification and calibration against measured data keep it honest.
Where it bites: "digital twin" is used loosely in marketing. Ask what the model actually computes, how it is validated and which decisions it informs.
Founder takeaway
Define the decision a digital twin will support and the accuracy it needs, then build the simplest model that meets that bar.
engineer review pending