The term 'digital' can be defined as; 'A branch of engineering knowledge and practice that deals with the creation and practical use of data or computerised devices, methods, systems and processes'. Ref The Gemini Principles. Centre for Digital Built Britain. December 2018.
A digital model is a computerised, data model of a building, product or some other object that describes the form of an existing or proposed object. Building information modelling (BIM) is a very broad term that describes the process of creating and managing a digital model of a building or other facility (such as a bridge, highway, tunnel and so on). See Building information modelling for more information.
A digital model should capture and represent all necessary data associated with the object.
Digital models can be used in the development of digital twins. Digital twins are typically associated with assets, processes, systems and other entities that physically exist. Digital models may be purely speculative.
According to the Gemini Principles, a digital twin is: 'A realistic digital representation of something physical. What distinguishes a digital twin from any other digital model is its connection to the physical twin.'