Phase transitions are involved in phenomena, ranging from the initial stages of the creation of the Universe, to the existence of biological objects. It is natural to ask whether any phenomena analogous to phase transitions are possible in disordered substances like liquids and glasses. The possibility of such transitions is still very much a matter of debate. Neither the nature nor the features of transformations in liquids and glasses are yet clear, nor is the nature of the order parameters. Investigations have shown that transformations in liquids and glasses lead to a drastic change of their physical properties and short-range order structure. The papers collected here aim to contribute to a better understanding of the physics of disordered systems and phase transformations in them. An unambiguous identification of transitions in liquids and glasses requires further high-precision experimental study of the thermodynamic and structural properties in the vicinity of transitions in order to test existing theoretical models and develop new, more accurate ones.