In the digital world, digital twins (DTs) have replaced physical models. They help researchers, urban planners, and other professionals improve processes and products and troubleshoot problems to achieve efficiencies, realize cost savings, and create new business opportunities. Digital twins are being used in manufacturing, health care, automotive, smart cities, natural resources, and others. For example, to move to zero carbon emissions, Las Vegas is partnering with Cityzenith, a digital twin technology developer, to gather and use data from buildings. The digital twin will enable monitoring and optimization of data to improve air quality, water management, and carbon emissions produced from major buildings. Researchers at Cambridge University have devised a way to use artificial intelligence (AI) to create “digital twins” of patients. The researchers posit that this technique can be used to predict individuals’ health issues over time and allow early intervention with personalized preventive care. These are just two recent examples of how digital twins are being used in different sectors.