Digital Twins: How Far from Ideas to Twins?

As a bridge from virtuality to reality, Digital Twin has increased in popularity since proposed. Ideas have been proposed theoretical and practical for digital twins. From theoretical perspective, digital twin is fusion of data mapping between modalities; from practical point of view, digital twin is scenario implementation based on the Internet of Things and models. From these two perspectives, we explore the researches from idea to realization of digital twins and discuss thoroughly.