Glasses are a kind of amorphous solids with scientific significance and wide applications vital to human life. "What is the nature of the glassy state" was one of the most difficult and challenging questions that has puzzled so many scientists for quite a long-time. Currently, there are mainly three different categories, including inorganic, organic and metallic glasses. Continuous random network, random coil, and random packing models were proposed to elucidate their glass formation, respectively. In view of practical applications, high-purity SiO2 glass for optical fiber, polymeric glass well-known as plastics, metallic glass for magnetic core material are eminent examples changing our lives. Glass is also the indispensable materials in history for the development of modern science including the astronomy, biology, medicine, information and communication. Even so, we are still far from fully understanding glass in aspects of their structure, phase transition, rheology, kinetics and thermodynamics.