Kurt Cagle explains a concept:
At the core of such digital twins is the notion of a model. A model, in the most basic definition of the word, is a proxy for a thing or process. A runway model, for instance, is a person who is intended to be a proxy for the viewer, showing off how a given garment looks. An artist’s model is a stand-in or proxy for the image, scene, or illustration that an artist is producing. An architectural model is a simulation of how a given building will look like when constructed, and with 3D rendering technology, such models can appear quite life-like. Additionally, though, the models can also simulate more than appearance – they can simulate structural integrity, strain analysis, and even chemistry interactions. We create models of stars, black holes, and neutron stars based upon our understanding of physics, and models of disease spread in the case of epidemics.
This is a really good explanation of the concept. Contrast with the explanation of, say, Azure Digital Twins. The first time I saw it, I thought one thing; then, when I read the intro page, I thought something different. Then, I walked through the demo and thought something yet again different. I might have just missed the part where it lays out exactly what a digital twin is and its importance but I do like Kurt’s explanation a lot more.