Disordered systems refer to physical or mathematical systems that lack a clear, organized structure. In these systems, the arrangement of components is random or chaotic, making it difficult to predict their behavior. Examples include gases where molecules move freely and glasses that have a disordered atomic arrangement. In contrast to ordered systems, like crystals with a repeating pattern, disordered systems can exhibit unique properties. They often display complex behaviors, such as phase transitions, where small changes in conditions can lead to significant shifts in the system's state. Understanding these systems is crucial in fields like physics and materials science.